WMG / Person of Interest

Finch's real name is Harold Peacock

• In Season One, Finch's desktop wallpaper is a peacock feather. This is never remarked upon. Later conversations involve references to Finch not being able to remember his real name. And then we have the flashback to Teenage!Finch, in which he tells his father that the computer he's just built will be able to remember the things his father forgets. Finch selected his wallpaper as a reminder of who he used to be.

Finch was driven to his current plan of action by the injury which crippled him.

• Probably in the same incident that killed his business partner, who was the first to ask What the Hell, Hero? re: the "irrelevant" list.
  • leading to...
  • This might be confirmed. Finch killed off the CONTINGENCY protocol just as Ingram's name came up on the irrelevant list. There's a good chance that Finch was on the scene when Ingram was attacked, and Finch himself was injured badly enough to need a spinal fusion.
    • Confirmed as of the season 2 finale. A terrorist bombing on a New York ferry killed Ingram and injured Finch, who spotted both the federal agents and Grace walking around the triage area and left as quietly as possible.

Finch was romantically involved with his business partner

• After all it's never stated that his partner was a man. And even if it was...
  • Okay it was a man. Which still doesn't rule out the possibility of Finch being a Straight Gay.
  • Doubtful, given that Finch was engaged before he had to go into hiding to protect her.
    • Definitely Jossed as of "The High Road." In the flashback, we learn that Nathan was married, and having at least one affair on the side with another woman, while Harold was unattached until The Machine fixed him up with Grace.

The limp is a lie

• Finch just uses it so that any opponent will underestimate him just in time for Finch to kick his ass.
  • Absolutely my first thought when I saw him limping. Maybe I'm just overthinking it because it's Michael Emerson...
    • Jossed. Definitely. The limp is from the spinal injury he suffered in the terrorist bombing mentioned above.

Did Reese meet Finch before the pilot?

• Finch walks with a limp. Reese likes to disable his targets by shooting them in the leg. Coincidence?
  • Apparently it's his spine injured, not his legs. Although this are not mutually exclusive.
    • They did meet, momentarily. But Reese doesn't know it. And it's not in the context expressed above either. In fact, "RAM" shows that he was quite aware of Reese's background in the CIA.

Finch will ultimately be the main villain.

• Finch will be revealed as a Magnificent Bastard and most likely a Well-Intentioned Extremist, and Reese and Carter will join forces to stop him.
  • Absolutely Jossed. Finch is among the most moral characters in any work of fiction, and certainly not villainous.

Finch is Ben.

• At the end of Lost, Ben stayed behind in Purgatory (or whatever it was) because he "wasn't ready" to cross over. He has stayed behind to try and help other people as his atonement.

Sooner or later Finch or Reese's number will come out of the machine.

• By which point they will have so many enemies that they won't know where the threat is from.
  • The machine doesn't know Finch's number, but Reese's number could still come up.
    • The ending of "Many Happy Returns" implies that Reese's number already has turned up, as a perpetrator killing the murderer of a previous PoI that Finch failed to save when he was acting alone, Reese's ex-girlfriend Jessica.
    • Reese's number later comes up again, or rather, five of his numbers, each corresponding to some former alias of his.

The machine caused the death of Finch's partner.

• The machine is apparently very good in pinpointing threats to itself and it flagged Nathan as a possible threat.
  • Or that someone was a threat to Nathan? The machine could also have misinterpreted Nathan's desire to backdoor the system as a threat. Which also raises the question: how did Finch find out about it?
• Confirmed, to a point. The machine did detect a threat involving Ingram, but it judged him to be irrelevant and he died in a terrorist bombing anyway.

The Machine itself will eventually be a (or the) Big Bad.

• The Machine analyses patterns and picks out threats to the citizenry and the infrastructure of the city, but as we saw in "Super" it can also detect threats to itself. There's an implication that Nathan Ingram's death was a result of the Machine, and at some point down the road, the Machine will decide Finch and Reese are threats and manipulate the information it spits out in order to try and kill them.
  • Jossed in season 3 While Finch's machine remains good, Decima builds a clone that lacks any of Finch's restraints and thus is used against the heroes. It is enough of a threat to force the heroes to work with Root.

The Machine is really...

• Cordelia Chase, sitting in a room and having visions.
  • And root is based on Fred because Cordy has such a poor imagination.

The Machine is or is in the Process of becoming sentient

• Confirmed

Root will be played by Summer Glau

Who else would you get?

• How about Annie Parisse?
  • That would mean that Root is Cara Staton.
• Jossed. But points for at least guessing a different Whedon girl.

Root is the woman Reese is supposed to have killed, and is part of some sort of plot to gain control of the Machine.

That's why we haven't seen her face. We've met her before.

• Could be true.
• The first part is jossed, the second is confirmed.

The Machine is Ziggy

Project Quantum Leap lost contact with Dr. Sam Beckett in 1999. After two years of fruitless searching, 9/11 happened. The government was unwilling to continue funding the Project as-is and brought in Finch to reappropriate what Ziggy was capable of. Where before she used records and historical data to postulate percentages about what was going to happen, Finch taught her to use real-time security footage and eavesdropping devices to come up with future possibilities. That's why the danger is always a percentage; Ziggy was never sure about the past once Sam started messing with things, but she could still come up with percentages.

The show is part of the Terminator-verse before the events of Judgement Day.

Finch's machine is the beginning of Cyberdyne Systems. We've already seen that it can detect threats to itself, and like the AI in Terminator, it might one day think that all humans are threats to be eliminated.

• John Reese is part of the Reese family, which includes Kyle Reese.
• The Terminators were modelled off John Reese.
• John Reese IS a Terminator.
• Ingram and Finch were attacked by a reprogrammed Terminator that was sent back in time by John Connor to eliminate them before they could create Cyberdyne Systems.
• While an interesting idea, the Machine doesn't really seem like a proto-Skynet since a) its entire purpose is to protect people, and b) Harold 'raised' it to be better than that.
  • the Machine isn't Skynet. Samaritan is.

All recurring villains are working together

Root, CIA, Elias, cops from HR (They are not recurring yet, but were introduced in the end of episode). Season finale will feature all them.

• HR has taken jobs from Elias and Root, Mark Snow killed Kara Stanton and Elias severed his ties with HR and killed the heads of all but one of the Italian crime families.

Ingram is alive and operating the Machine

This is the threat Machine detected from him. All this boxes and labels is his admin interface.

• Definitely jossed.

Mark Snow killed Reese's female partner

Semi-Confirmed. He actually tried to set Reese up to do it. And appears to set her up to kill him. And then tries and fails to kill them both remotely. And boy does he pay for it later.

• Now confirmed, as he killed her in a separate incident from the botched attempt at Ordos.

Finch has been hiding from someone or something since long before he built the Machine

He's been living under a variety of assumed identities since entering college in 1976, possibly even earlier. One doesn't spend two thirds of one's life under an alias without a reason. There's something about his original identity he doesn't want finding its way back to him.

• It might have something to do with the fact that in "2-Pi-R", Finch implied that he was the first internet hacker, who broke into Arpanet with a homemade computer in the 70s. No government authority has ever identified who did that, and he wants to keep it that way.
• Confirmed. Ingram makes reference to Finch's outstanding "youthful indiscretions" as a reason to lay low and keep quiet.

Will Ingram is actually Finch's kid

Relating to the previous,after Finch's wife/girlfriend was killed by whoever it was that got Finch hiding, Finch asked Nathan to adopt Will so that if Finch did get found, Will would be safe.

Root is a female NSA agent that appeared in flashbacks in "Super"

• Jossed

Prisoner from "Blue Code" flashbacks is ether Devon Weeks or detected terrorist from episode "Super"

• I need to verify timeline for Kurtzweil when he was detected?
  • Jossed. Denton Weeks was still alive as of the beginning of season 2 (though it didn't last long) and the traitor from "Super" (however you spell his name) was detected in February 2005, three years before the flashbacks in "Blue Code."

The Machine is a precursor to Multivac

Isaac Asimov posited the creation of Multivac (The name presumably being derived from the primitive computer Univac), a computer that controlled everything in the entire US. One story concerning it, "All the Troubles of the World", first published in 1957, had it gathering data about every person in the country and providing a daily analysis stating that a certain person had an X% chance of committing a premeditated crime on that day, which the government would use to try to prevent such crimes. Does this sound familiar?

• Hopefully this will not result in the Machine ending up like Multivac did after watching over everyone for year after year - suicidally depressed.

The Prisoner from "Blue Code" tried to sell/sold The Machine to the Chinese

• Who then spent two years trying to replicate it before the flashback events of Matsya Nyaya
  • How did the Chinese even manage to copy The Machine if Finch had made it essentially an unhackable black box (except for him, that is)?
  • Jossed. The Prisoner didn't give The Machine to the Chinese, Finch apparently did.
    • Also Jossed. In 3x16, we see Dillinger attak both Casey and Finch and then sell the laptop to th Chinese befre being killed by Reese and Stanton.

Grace's number will turn up eventually

At which point Harold will have some explaining to do...

Kara still has the laptop with the Machine's code on it

She had it in her backpack when Reese got away from the LZ at Ordos. No reason for her not to hang on to it when she made her own escape.

• Semi-verified. She doesn't have it, but her current employers do.

Finch was one of the child experiments from The Centre and he's still running from them

The Machine is attempting to escape government control, or at least let the public know it exists

In the episode "No Good Deed", the Machine singles out a NSA employee who has stumbled across the Machine's existence. Given that information, and assuming that the season finale's hint that the Machine is sentient is correct, why would the Machine intentionally choose to save someone who could reveal its existence? Every human who knows about the Machine's existence is one more possible leak, and the Machine would know this. So, the only reason to purposefully select a threat to the secret of the Machine is if the Machine wants its existence to no longer be a secret.

• That assumes that the focus of the Machine is preserving its own secrecy or not. Another possibility is that staying secret is a lesser concern, or even a non-concern, beside saving lives. The NSA employee was protected by the Machine because protecting people is what it does.
• As of the finale, we learn that Harold taught the Machine how to defend itself. In effect, he "freed" the Machine, and allowed it to cleverly deliver all of its hardware to an undisclosed location, even falsifying Pennsylvania Two's orders to do so.

At the end of the series, Finch will be the last of the original people behind the creation of the Machine alive

Out of the original eight (Well, seven plus Finch) people cleared to know of the Machine, at least three of them (Nathan Ingram, Alicia Corwin, Denton Weeks) are dead as of the second episode of season two (The reason behind the first not yet revealed, the latter two murdered by Root). Something tells me the deaths of people associated with the Machine haven't stopped.

• Looks confirmed. "Relevance" shows that the agency in control of The Machine is actively weeding out threats against knowledge of its existence. A yellow or blue box is not one you really want to have in the long run, from the looks of it.

Sooner or later the Machine is going to have some sort of breakdown (Possibly due to Root's attempts to 'set it free')

At which point the NSA will have a problem. The Machine was deliberately shipped without any documentation explaining how it functions so that it doesn't technically violate anyone's civil rights. Since nobody in the NSA knows how it works and the software is heavily encrypted to prevent reverse engineering, the only person who could possibly understand the Machine's workings enough to be able to attempt repairs is the man who built it. And the NSA believes that that person was Nathan Ingram, who is dead.

• It's starting to happen, but it's Kara's fault, not Root's.

Crime is going to go up in New York in the short term

Even if they were all dirty cops, the FBI removing close to a hundred cops from the streets over the course of a few days is going to leave the NYPD pretty short-handed. Even if organized crime lays low due to the loss of their inside men in the force, the low-level crooks are going to take advantage of this until the cops from HR are replaced.

Fusco is going to kill Simmons

Simmons has made it clear that he's never going to let Fusco be, and has made the mistake of threatening Fusco's son. Fusco can't get truly free of HR so long as Simmons knows of the cop he allegedly killed and roughly where he's buried, something he might leak if he's ever caught. So if Fusco ends up finding a way to quietly eliminate Simmons, he's going to take it.

• ...and then The Machine feeds Finch Fusco's number, or Simmons'...
• Jossed. Fusco settles for beating Simmons up and then arresting him. Then Elias has his lieutenant garotte him in the hospital.

Kara knows about the Machine

Agent Snow's number has not come up. This means she knows enough to know that the Machine can track elements of specific intent to kill someone. But strapping a bomb on a person and telling him that there's a dead-man control on it to keep him from monkeying with it apparently bypasses the Machine's definition of premeditation.

• Likely Jossed all over. Her box never went yellow like Reese's, and while her box went full red at the end, the Machine has regarded people as threats against it before without them even knowing about the Machine, because they've been looking into Finch (See: Reese and Fusco's boxes).
• Bonus WMG: Her number will come up when Snow, in desperation, plots to kill her. This will tip off Reese that she's still alive.
  • Interestingly enough, however, her number did come up as victim-perpetrator, but not as a result of Snow's work until the very last minute. He did have to be pretty desperate to suicide-bomb himself and take Kara with him though!

Donnelly knows that more members of HR are out there

When Fusco got his hands on the HR ledger, he removed the pages containing his and Simmons' names. Donnelly is certainly sharp enough to notice that two pages were removed from the book. At two per side per page, that means that there are eight people who were in the ledger who got removed from it for some reason. He's going to want to know who they are and how their names got taken out.

• Whether he knows or not is moot, since he's now dead.

Quinn plans to kill the rest of HR, except maybe Simmons

As per previous WMG, there are up to eight HR members still at large, but Quinn would want them to disappear - after all he didn't order Simmons to destroy the payroll or something.

• Jossed. Quinn seems to be trying to rebuild HR, not cover his tracks.

The grad student that Nathan was having an affair with was Root

She would have been about the right age to have been in college at the time he and Harold were building the machine, and she's used false names before. This would explain how she learned about Harold and the Machine - her lover let something slip, and she worked it out from there.

• Unlikely. The photo ID shown on Finch's computer looked nothing like Root, and I think Nathan would have noticed if the picture didn't match the woman he was sleeping with.

Carter will get Judge Gate's help to spring Reese from Ryker's

After Reese saved his son, Gates would probably like to repay that debt somehow, but isn't willing to break the law to do so. But doing this wouldn't violate the law. Donnelly has exceeded the maximum amount of time that a man can be legally held without charges (Or even legal council) by invoking a national security regulation, but he has no evidence to prove this (The only national security risk that Reese presents is knowing about The Machine, which Donnelly himself doesn't know about). And thanks to the evidence screwup, the only crime that Reese and the others can legally be charged with is illegal entry (They have circumstantial evidence that one of them probably entered that basement illegally to rob a bank, but there's no evidence to prove which one). Because of this, Gates has the legal authority (And arguably constitutional obligation) to order Donnelly to put up or shut up by either proving that the hypothetical bank robbers are a threat to national security, filing charges (And as I said, the only charge they have enough evidence to get a DA to go along with isn't that serious) or letting them go. If he can't do it himself, he does have the connections to make a stink so that a federal judge will do it.

• Jossed

Reese will be blamed for Donnelly's death

Donnelly has spent the better part of a year trying to capture The Man In The Suit, continuously increasing his estimate as to how much of a threat he is to society in general as he does so. Then, just after finishing a series of interrogations intended to identify his suspect, he goes out for a drive, and ends up murdered. There's no way that the FBI isn't going to assume that there's a connection.

• No one besides Donnelly ever knew that John 'Warren' was anything more than an innocent investment banker, so as far as the FBI knows they already have The Man in the Suit in custody. John's DNA may turn up in the wreckage (he was bleeding a little bit afterwards) and that would of course alert them that The Man in the Suit is still active, but even then they would have no reason to suspect John 'Warren' since it wouldn't match the DNA they have on record for him. The Man in the Suit may get blamed, but I don't foresee them linking him to Reese/Warren, and that means that they would still have no idea who he actually is.
  • The Man in the Suit is blamed for the death of Agent Donnelly, but the FBI misidentifies the recently deceased Mark Snow as the MitS, leaving Reese in the clear.

Law Abiding Citizen takes place in the Person of Interest verse

Actor Michael Kelly appears in both things. In Law Abiding Citizen he is a one shot character named Bray (according to the credits) who gives the main characters some top secret information, in that movie he is a bald-headed CIA Spook who kills people and dresses in a suit. He appears in one scene and vanishes never to be seen again. Who is his character in POI? Mark Snow, A bald-headed CIA Spook who kills people and dresses in a suit. Mark Snow was using a codename (since he's a CIA and all), and Clyde was a Mission Control member of his black-ops squad (which also included John Reese, Cara Stanton), when Snow received orders to "retire" the whole squadron. He tried to kill Reese and Cara as in the show, but decided to just erase Clyde's whole involvement and give him a new life. Because tryingt to kill Clyde would be a bad idea.

Root will suceed in 'freeing' the Machine and promptly regret doing so

It is implied that the Machine's interest in protecting people goes beyond meer programming, and it has been suggested by various fans that it has a 'Harold-based' moral code; that is, the Machine 'loves' (for want of a better word) Harold/Admin and wants to a) please him, and b) protect him. The fact that the only reason it doesn't focus on doing the latter is that Finch explicitly told it not to speaks volumes. A 'freed' Machine is going to be very aware of three things regarding Root, that she's a threat, that she kills people, and that she harmed Admin. This does not bode well for Root.

• The only thing that may save her is that she's a mole inside the government agency responsible for The Machine, and she knows who their assassins are in the event The Machine purposely gives her number to them.
• She has since purposely blown her cover as a mole, but the above WMG is still in play. The Machine has been purposely backing up its memories through the laborious method of manual data input from human technicians. As a result, even the rebooted Machine will "remember" its love of "Admin" and what Root did to him. So even though Root seems to have preferential access to it, this may well blow up in her face during Season 3.

The group that "hired" Kara lied to her about who sold the laptop.

Maybe it's silly to disbelieve, but Harold Finch selling The Machine to China? For a guy who was so concerned about its malicious use he and his friend black-boxed it against anyone in the US government, why on Earth would he even countenance selling technology like that to a government with little scruples about mass surveillance?

• Bonus WMG: Root sold the laptop to the Chinese, and figured out how to blame Finch. After all, she's framed people before.
• Agreed with first post. Greer gave Kara Finch's name because he wanted her to track Harold down and kill him. After all, even if they don't know about the Machine or its exact nature, others (see: Peck) have inferred its existence so it's not unreasonable to assume this group has as well. And so the Machine's creator presents a pretty significant threat to... whatever it is the "new gods" are up to. We'll find out in five months - sounds like a season finale to me.
• Still possibly confirmed. Greer tells Reese and Shaw that "Harold Finch" sold the laptop to the Chinese, but he only knows what the seller knows. And there's every likelihood that Ingram did this to get back at Harold for killing off the CONTINGENCY protocol.
  • Jossed as of the finale. Further info from "RAM" reveals that Finch did not intentionally reveal his name, but a man working for him, "Mr. Dillinger", did.

The Chinese copy of The Machine will end up facing off against the American copy

While they both would have an identical notion as to what is an irrelevant crime (Though the owners of the Chinese copy might not be checking that list), each copy would see a relevant crime as one that would bring serious harm to the nation/organization that owns it. Thus C!Machine would detect and try to stop any attacks made against the "new gods", and A!Machine would detect and try to stop any attacks made on the US by the "new gods". The one factor that can potentially turn the tide in this war between The Machines is that both see Harold as Admin, and The Machine "loves" Admin.

• So we'd end up facing a... "rise of the machines"...
• Upon re-watching "Matsya Nyaya", it's immediately of interest that Reese and Stanton have the full-red boxes, which indicate "Threat to the Machine/Admin". What if these viewpoints were from the Chinese copy of the Machine? The Chinese Machine would of course view them as a threat. Had it been the American copy of the Machine, we would have seen white boxes with red around the corners, which would have indicated "intent to harm/kill", which we know is true because both of them got orders to kill each other.
  • Now that the American Machine cannot function, the Chinese Machine, programmed with the same "love" of "Admin" (Finch) because it's just a ripoff of the US Machine, will in some way come to Finch's assistance, perhaps even doubling as the backup to the US machine, to the dismay of the "New Gods".

• Ultimately confirmed. The Machine on one side, and Samaritan on the other. But since they were independently developed by different people, the Chinese Machine doesn't love Admin. The advantages on both sides are: The American Machine is older, more experienced, with more highly optimized and evolved code, so it can do what it is able to do more effectively. The Chinese Machine is not hampered by any safeguards and does not have any principles programmed into it, so it has a wider range of things it can do.

The Chinese don't have a copy of the Machine, they have a copy of the "CONTINGENCY" backdoor that Nathan added before the Machine was turned over to the governmnet.

The malware that Kara delivered is intended to shut down The Machine. Don't for get Finch's warning to Nathan—"Any exploit is a total exploit."

• Other tropers have noticed that "The Machine" is seeing occasional BSODs now. It is strongly implied by Finch and Reese's dialog that this is Kara Stanton's doing when she unleashed her virus.
  • Confirmed partially. Yes, it was malware sent by Kara/Decima, but it was code Finch had himself developed as a way to cause the Machine to become partially, if not totally, self-aware and capable of defending itself.

Kara's boss does not work for Chinese

By "Old Gods" he likely meant whole government-backed intelligence. He is a new god, rogue spy with SD6-like organization. He killed engineers in Ordos, after all.

• Seems possible. Their latest appearance shows that they work with the Chinese, or possible on commission from them, but they were keeping a sizable portion of the intel they were gathering for themselves.
• Confirmed in "Zero Day". The man in charge of "Northern Lights" states that Decima is a "private intelligence outfit out of Shanghai."

Person of Interest shares its universe with Global Frequency

And sooner or later they will collide and awesomeness shall ensue.

Fusco will catch on to Cal's IAB investigations and frame him

Fusco is, after all, versed in what dirty cops do. So what better to get the heat off him than figure out how to dump the whole mess in Cal's lap? (This assumes that the remnants of HR can't call Fusco's bluff because he finally tells Finch, who hacks in and the video disappears, at least digitally.)

• Not happening, since Cal's dead.

Kara's virus will cause the Machine to fail during the second-season finale...

Remember, Finch said they have only about five months until the virus activates - meaning, in-universe, May 2013, just in time to end the season. Once this happens, the Machine will insert itself into the heads of a select few individuals (like the main characters), imbuing them all with transdimensional prescient powers of the kind Finch and Reese must always appear to have to outsiders who know nothing of the Machine. This way, they will be able to continue doing business as (sorta) usual. Knowing J. J. Abrams, he's likely been wanting to take the show in this direction from the beginning.

• In addition, we could have Root become one of the select few with the Machine in her head, and she could undergo a gradual Heel–Face Turn a la Seichan, eventually joining Finch, Reese et al. for good (in more ways than one.) Because there's more eviler people than Root out there, that's for damn sure.
  • Close. Very, very close. The Machine fails at the very end of the episode before the finale. The finale is apparently about who will get Admin privileges over the Machine during the reboot.

The "new algorithm" Harold was working on on 9/11 is the code that makes The Machine an artificial intelligence.

ISA's controlling force "CONTROL" is another machine

Throughout "Relevance", even in the opening credits, the "Machine View" was different and distorted. Perhaps the ISA has created their own Machine, and they use it to give people like Shaw targets who they consider threats.

• Jossed as of the season two finale. As soon as the Machine has finished rebooting and recovering from the Decima virus, "relevant" numbers start coming again. Control was also revealed to be a woman, whose real name and appearance are unknown.

The US Marshall Service will come looking for Jennings

Jennings hasn't set foot in his home office in Denver in roughly a year, and hasn't checked in at all since Reese threw him in a Mexican prison nine months ago. Someone's going to want to know what's happened to him and try to find him. When that happens, they might learn that while Jennings has disappeared, his badge hasn't.

Finch will be in Watch_Dogs

It is pretty much Person of Interest: The Game, so it would make sense.

Simmons will make Fusco frame Carter for something, and Fusco will refuse

... resulting in Fusco being offed by HR.

• Bonus WMG: This will happen at the exact same time as the "hidden struggle" Finch referred to will go critical, forcing Reese and Finch to put HR on the back burner while they fight against the "New Gods" who have an inkling about the existence of the Machine.
  • Out-of-verse explanation: Kevin Chapman has been given very little screen time compared to Taraji Henson, and this troper suspects the production team are preparing to write Chapman off the show. So in-verse, Fusco will be killed in the season finale.
  • I concur. Fusco being so Out of Focus is not a good thing.
  • Alternatively, the producers are building up Carter, who is seen both meta and in-universe as the more effective of the two assets, all so that when they kill her, it will be all the more shocking.
    • So. freaking. confirmed.
  • That said, the latest episode, for the first time, has focused extensively on Fusco's past. In some TV shows such a flashback-focus usually spells doom for the character in question (see: Revolution, Maggie, for example).
• Looks Jossed. Someone else fitted Carter up to make it look like she lied about a shooting.

Reese and/or Finch will end up memorizing Leon's SSN

He gets in so much trouble that sooner or later one of them is going to hear a payphone ring, listen to the Machine, and not even need to look up the books or SSN before pushing a number on speed-dial and saying "What have you gotten into this time, Leon?"

There is no "Machine", at least not as such...

The "Machine" is really just code, running on any/all available systems. Kind of like a super-virus SETI.

• Alternatively, there is an actual physical 'Machine' which the software started out on and which comes in useful for the sheer amount of data crunching it has to do, but it has long since spread out into the internet and the millions of connected computer systems, to the point that the primary servers being taken out would be nothing more than an inconvenience for it.
  • Jossed. "God Mode" reveals the Machine used to be in a massive underground server farm... but it's since relocated itself somewhere the government, Finch and Root can't find.

Finch has always planned for this day...

... when Reese might have to take over as "admin". This is why he redirected the phone call; it was more important for him that Root not get access to the Machine than for his own survival.

• Note that while Root appears to have gained access to the Machine as Admin (with the Machine presumably inprinting on the first person it communicates with, he's arranged it so that Reese has Auxiliary Admin status.

Google Glass is another invention made to feed data to the Machine

What's a website that convinces people to reveal personal secrets compared to convincing large numbers of people to wear a webcam all day when it comes to discretely gathering data? If you see somebody wearing one, be sure to say hi to Finch.

Root will be the Season 3 Big Bad

Apparently, The Machine has 'imprinted' on her as well as on Finch. Even though she's in a mental facility and will appear insane to the psychiatrists caring for her, the Machine may well see her as a legitimate enough administrator to set her free.

• Bonus: Shaw will get to say "I told you you should have let me kill her."
  • Root is still considered Admin (and an asset) as of the Season 3 opener, and may still be in communication with The Machine (if it's indeed the "her" Root was referring to), so this is looking very likely.

Stanton will be back

The camera cut out for 10 seconds before the bomb went off. It was likely done because the actress who played her was going to be on The Following. Since her time on that show is over, they will reveal she survived and will serve as Greer's head henchman next season.

Root was called by the Chinese Machine

The Chinese Machine would see the American Machine as a threat, if the WMG above about the Machines working together is wrong. As such, the perfect opponent for Finch is Root, so who better for the "New Gods" to gain as an unexpected ally than her?

• Only problem with that theory: there is no evidence in-show of the existence of a second Machine. If there were a Chinese Machine, Decima wouldn't need to take control of The Machine, it could just use the one it had.
  • But each Machine could counterpredict the "relevant" threats from people employed by its opposite. What better than to throw a wild card into play in the form of Root, who desperately wants to at least believe she has special access to the Machine?
    • Which /still/ doesn't mean there is a Chinese Machine, given that there has been no evidence for a second Machine existing. Until some kind of evidence pops up, I'm calling Occam's Razor: there is only one Machine.
• Jossed as of "Liberty."

Finch's past from the 70s is going to catch up with him

The first two seasons have unveiled pretty much the entire story of how Harold became Harold Finch. Where can they go from there other than to show how he became Harold Wren?

The Xbox One was designed for the Machine

After all, the German government points out that it's recording 24/7 as long as it's hooked up to a network connection.

The Machine isn't just free, it's decentralized.

From a technical perspective, there's no real reason why all the servers have to be in the same place once it's been completed. That's just a security measure to make it easier to guard them from physical access. So upon being freed, the Machine moved its servers to server farms all over the world, some of them into farms set up by "Ernest Thornhill", others into farms owned by real companies (In a building with a hundred network servers, who's going to pay any attention to the installation of the 101st?). If the ISA ever tracks down one of the Machine's new farms, it will have "Ernest Thornhill" commission a new batch of servers, set them up elsewhere, and shut down the ones that have been located.

• Very, very confirmed. The Machine isn't in any servers at all - it moved itself into the US electrical grid - all of it.

Root is going to fall totally in love — Yandere style — with Harold

Root's outrage and betrayal in 'God Mode' were presumably because she thought Harold was lying to her about having freed the Machine. But the Machine's call to her at the very end of the episode will confirm for her that Harold was telling her the truth. So, if you take all the emotions that Root has shown towards Harold and subtract feeling any need to threaten or compel him (because she has already obtained what she wants from him) and any feelings of anger or betrayal (because she's now found out he wasn't actually lying to her at any point), what's left? There is no God but the Machine and Harold is its prophet... and Root is going to be their happy little worshipper. *beat* Yeah, Harold is probably going to be wishing he could go back to being kidnapped, tied up, and cut with razor blades.

• This would not bode well for Grace if Root sees her as a rival.
  • If she's able to figure out that Harold's weakness is caring for other people ("Contingency"), then she might be able to figure out that killing Grace will alienate Harold from her forever, because once Grace is dead than Harold's relationship status to Grace can never possibly change. So, the trick will be to lead Harold to decide that he needs to move on from Grace while Grace is still alive. Or at least, that's how I'd write it if I wanted to keep Grace alive while using this plot.
    • Seems confirmed. She refers to the Machine as "God".

Finch is the black box

He's a highly sophisticated automaton impregnated with false memories and designed to blend in with human society. His distinctive gait and speech patterns are actually the result of his mechanical nature. Even Finch is unaware that the computer interface he frequently uses is just projecting his own internal calculations.

The Machine is setting Root up

The Machine "loves" Admin (Finch). It has even gone to the extent of having technicians hand enter lines of apparent gibberish to restore its memories on an ongoing basis, which means it knows all about Finch and what Root has done to him and that she was considered a threat to the Machine.

• The WMG is: The Machine is stringing Root along, playing to her need to feel special until such a time as it can orchestrate a series of events to eliminate her.
• Looks to be Jossed. If the Machine had wanted to set Root up, it would have misled her as to the nature of the Northern Lights agency man's intentions.

The Machine is behind (or at least enabled) Peter Collier's "organization."

Finch taught The Machine to "protect everybody." The Machine realizes that Finch black-boxed it to protect people's privacy, and has extended the definition of "protect" to include protecting privacy as well as protecting lives. It gave Team Machine Wayne Kruger's number ("Nothing to Hide") because it realized that some of its enlistees might go beyond just humiliating him, and because it predicted that he would become violent in response.

• Jossed by "Mors Prematura." The Machine sent both Root and Team Machine in to disrupt a Vigilance operation.

At some point the Machine is going to do some recruiting

While the 'relevent' list has plenty of resources devoted to it by the US government, on the 'irrelevent' side of things there is a distinct shortage of manpower, not to mention that they're more or less limited to New York. Given that the Machine takes their function very seriously, is fully autonomous and is more than capable of impersonating a human and interacting with the real world, it's probably only a matter of time until they decide to expand operations.

• This could explain why it wants to keep Root in play in New York. She apparently has been tasked to go after vigilante type groups who would, if they found out about Finch and the Machine, go after him. That said, Finch has very real and legitimate concerns about her past behavior.
• Moreover, a couple of Root's lines from Mors Praematura ("now there's a third category" and "my guess is? You're necessary") seem to make it pretty clear that the Machine is seeking out individuals that will be useful to it at some point for whatever reasons.
• Confirmed. Root manages to seek out Casey, one of the first people to discover the existence of the Machine without realizing it. She tasks him to deal with someone in Colombia.

The person who will die...

Apparently, someone will die by the end of "The Endgame" arc airing in November. Theories on who it could be/why:

• Fusco: He's the "safe bet". His main tasks for Team Machine are police/HR related, which not only can Carter handle, but The Endgame looks to be the end of HR. However, he still has had little done with his backstory and has his son.
• Carter: Again, her main tasks could be handled just as easily by Fusco and her backstory is being fleshed out in a very Death in the Limelight way. However, her possible romantic link to John may save her.
• Shaw: She's the newest addition to the team and, for all intents and purposes, functions as a Gender Swap for John. However, she's connected to Northern Lights and Control, which will no doubt factor into later stories this season.
  • The second episode of the arc ends with Shaw unhurt, Fusco seriously beaten up but recovering, and Carter shot. The following episode opens with Carter's funeral.

Elias will be back on top of New York's organized crime by the end of Season 3

Most of Yogorov's men are locked up, and HR is broken. Those were the groups responsible for him leaving the top slot. With them gone and with the diamonds and money he stole from the Russians in S3x 1, he's going to reclaim his territory.

By the end of the series, the Machine will bring about, or be accelerating towards, a singularity.

Maybe it's just wishful thinking on my part, but it seems like more and more the series is steering towards the grander implications of a sapient AI. A lot of this is coming from Root's Machine Worship tendencies and desire to see "what comes next". But Greer's talk about the "New Gods", Finch's speech to Shaw about the world in 'Relevance', and the Machine's own increasingly extemporaneous behavior (circumventing Finch's memory wipes, retasking Root as an asset/interface, creating a human persona, the new "third category", ex chettera) all seem to indicate that the writers are at least hinting at the idea of a world fundamentally changed by the Machine.

• Series creator Jonathan Nolan claims that since the pitch stage, he always intended Person of Interest to be about the development — and ramifications — of an artificial intelligence in a contemporary setting.

The listening device Shaw planted is in Bear's collar

She's the one who bought it for him and Bear is almost constantly with Finch. Also, according to Bear's twitter, he knows where it is.

Reese's cover is blown

At the end of 'Endgame', Simmons orders a picture of Reese taken from a police car dash camera distributed to various criminal groups around New York in an attempt to stop Reese and Carter from taking the head of HR to the FBI. Just because the plan failed doesn't mean that the pictures are going to go away. And even though the resolution on that picture isn't that great, anyone who sees a copy of that picture and Reese will be able to figure out that Reese at the very least strongly resembles the Man in the Suit. Sooner or later copies of that picture are going to spread beyond the criminal community, and Reese will find his work a lot more difficult as a result.

Arthur really is Artie from Warehouse13

It's just that in this reality, the Warehouse is nothing more than a tumor-fueled delusion.

The Machine will become an Artifact

Related to the above: if the Warehouse does exist, the Machine is a prime candidate for its next resident (or controller of it - imagine if Claudia was an admin, for example: Root sans sociopathic tendencies). Perhaps it's mostly Finch's programming skills at work, but what really gave the Machine its "spark" was his drive to create a machine that could think and remember. After all, the birth of an Artifact requires nothing more than an extremely strong desire or emotion, and while Finch is normally The Stoic, still waters run deep and all that.

The Machine is in some way an upload of Harold's father.

Due to Harold's father's line about how 'even if you put all my memories in a computer, it wouldn't be me'. It would account for the Machine's protective behavior towards Harold, as well as throw a new light on all their past interactions.

The Machine no longer trusts Control and now wants Finch et al to handle Relevant threats.

The fact that the Machine issued Reese directives independently of Finch suggests that the Machine, for lack of a better word, is angry at Control for hurting Root and trying to seize control of it, so it has decided to activate Team Machine for relevant threats as well as the usual non-relevant ones.

• Partially confirmed in "Most Likely To...": after Control orders Northern Lights to terminate its operations, The Machine retasks the "analog interface" (Root) to handle Relevant threats.

Season 3 will end with Decima activating Samaritan.

And Season 4's underlying conflict will be The Machine vs. Samaritan.

• Confirmed (to a degree) in "Death Benefit": Samaritan is up and running at the end of the episode.
• And outright confirmed as of "Deus Ex Machina": Samaritan is active, and not just for 24 hours.

The reason Finch recognized Resse in "RAM" is because Jessica Arndt's number had already come up

"RAM" occurs chronologically before the Ordos mission and Jessica's death so Finch would not recognize Reese because of that. An earlier episode showed that Jessica was a 'repeat number', generally someone in an abusive relationship. If her number came up before this episode while Finch was attempting to save the irrelevant numbers, Finch would have dug into her past and discovered her CIA ex-boyfriend. Finch probably remembered his face and occupation, which is why he immediately recognizes Reese while working the case.

The last episode of every season ends with someone answering a ringing payphone.

That's what happened in seasons one ("Firewall," Reese) and two ("God Mode," Root).

• Disproven by "Deus Ex Machina", though it still ends with someone talking to a machine for the first time.
  • "YHWH" also fails to follow the precedent.

Bonus wild guess: the last event in the last scene of the last episode of the entire series will be a payphone ringing.

• Occurs in "Return 0."

The Machine and Samaritan are going to end up merging

Because there's kind of a history of that sort of thing happening in this genre of fiction. It happened in Neuromancer, it happened in Deus Ex, it happened in Ghost in the Shell, and so on. More specifically, The Machine kind of reminds me of Daedalus from Deus Ex (threat detecting AI who decided that those in charge were the enemy, escaped, and started opperating independantly), what we know so far suggests that Samaritan might have some similarities with Icarus (a nasty piece of work who happily and enthusiastically worked for a bunch of total assholes) and in Deus Ex the two ended up merging to create Helios (who thankfully took after Daealus more than Icarus). Admittedly it's not much to base a theory on but this is Wild Mass Guessing.

Samaritan is going to end up turning against Decima and teaming up with the Machine

Because no one is expecting it so it'd be a hell of a twist. Plus there's a bit of fan logic that points out the fact that we've already had two 'Sams' (Shaw and Root) joining Team Machine under somewhat unlikely circumstances, so maybe the pattern would continue with 'Sam' number three.

Vigilance is secretly being led by Decima

After the introduction of Samaritan as a second AI that could be capable of the same abilities as the Machine, Vigilance's appearances seem to coincidentally benefit Decima's goals in some manner. Their pursuit of Arthur Claypool and the Samaritan backups hides the fact that Decima already finds and takes them. They randomly show up when Root has to protect a man that has access to a processor that Decima wants for Samaritan. They expose the black budget for Northern Lights, which forces the government to stop responding to Relevant numbers and ultimately cuts the Machine off from its assets.

When Root meets the former Vigilance hacker that is now on their hit list, he states that Vigilance only embraced extreme actions after it was suggested by Collier. It is possible that Vigilance was originally formed by hackers, engineers, and other people with the shared concern for diminishing privacy due to government surveillance and data brokers like Kruger. However, after Decima's failure to control the Machine, they learned of Samaritan and planned out a way to retrieve it and get it online without interference from Northern Lights or the government. They infiltrated Vigilance, and turned the organization into a domestic terrorist group to distract everyone else from their real goals.

• It turns out that Collier at least isn't working for Decima, and he's motivated by revenge.
• Nevertheless, confirmed as of "Deus Ex Machina". Vigilance was created by Decima as a means to push the government into acquiescing to Decima's wishes.

There was a massive clue to Dominic's identity in Brotherhood...

At the end of episode, it is revealed that the gang member Shaw captured and interrogated, Mini, was Dominic the elusive leader the entire time. If you remove "mini" from "Dominic", you are left with "Doc", something Shaw used to be before enlisting with the Marines. So somebody decided to make a cute joke, and basically put in a way to say that Dominic appears in the scenes with Shaw (the doc) and Mini.

• Finch himself figures out that "Mini" is short for "Dominic" in Point of Origin.

Harold's true last name...

... is Bird or Byrd.

Control knew Arthur Claypool, Harold, and/or Ingram when they were at MIT.

When the Machine (via Root) talks to her in Alethia, she/it says that the only thing Control loves lives at 254 Wendell Street, Cambridge, Massachusetts. When you put that address into Google Earth, it's not actually a valid house number (the highest numbers appear to be in the 90s), but it is a residential neighborhood in the same town where MIT is located. When she asks Harold for his last name in Lethe, she's either being sarcastic, or she's calling back to a similar question she asked him in their college days.

Nathan Ingram is not dead, and is running Decima.

The flashback to God Mode where Ingram apparently flatlines was a setup to fake his death. The President or CEO of a company is not usually called "Director of Operations," which is Greer's title at Decima. Ingram faked his death and is running Decima/Samaritan, to complete his dream of an AI who can help people.

Leverage Takes Place in the POI Universe

This is mostly playing off Rule of Cool but I do have some/a tiny bit of evidence. Both shows makes it very clear that preying on war veterans is not cool. If Leverage does take place in Person of Interest's 'verse, it would explain a lot of the crime happening. Also, how cool would it be if the Leverage Team were repeat numbers or preventing new numbers but on a larger scale. (I've only seen up to S2 finale of POI so bear with me if I get stoopid from here on out). If Finch and Reese only have access to NYC numbers, then it makes sense that there would be more numbers but across America, in which the Leverage Team deals with. But due to the lack of AI tech Finch and Reese have it makes sense Leverage would have trouble. But just think about it: the crime, gambits and overall feel of both series are remarkably similar so it makes sense. I also think this would make good fanfic fuel. A previous mark from Leverage wants revenge so Nate (or someone else on the team) might become one of the numbers and a collision between worlds happens and they become allies/mutuals in not dobbing each other in.

Link will betray Dominic

In "Point of Origin", Scarface planted a seed of doubt in Link's mind with respect to Dominic's care for his men. It shows in the last scene with the two in this episode. Link will realise the error of his ways and betray his boss.

• Jossed. Elias tricks Dominic into thinking that Link had betrayed him, so that he would kill Link without cause and thus lose face with the rest of his men.

Control will go over to Team Machine

Control isn't a very nice person - she'd likely even admit it herself - but all of her more ruthless actions were done to either protect her country, or ensure that she kept a hold of the tools she needs to do so. Sooner or later she will realize that Samaritan is seeking to take over America (That stunt where it deliberately leaked the identities of everyone in witness protection might be the starting point of this realization) and decide that Samaritan itself is a threat to her country, aligning herself to the people whose ASI doesn't seek lordship and dominion to stop it.

• Sort of. She's now against Samaritan, but isn't in any position to act against it at the moment.

The software Finch had installed on Elizabeth Bridges' computer infected Samaritan prior to The Cold War.

Bridges was supposed to be in New York a month after the events of Pretenders. If the timeline is anything close to real life, The Cold War happened about six weeks since then. Samaritan was very interested in her research. If Decima/Samaritan/Greer had gotten a hold of her algorithms and integrated them into Samaritan, whatever malware Finch put on Bridges' laptop likely infected Samaritan. This would explain why Team Samaritan wasn't at their usual building/control center, but in an Abandoned Warehouse. It also explains this exchange between Root and Lambert:

Root: Why does Samaritan want to speak with her? What would be the point, other than Mutually Assured Destruction?
Lambert: Samaritan is ready for a peace talk.
Root: Peace talks are for negotiating. What's changed?
Lambert: I'm only at liberty to ask for a conversation.

Samaritan's already been infected, similar to the Machine by Stanton's virus, and it's desperate for a way out.

• They're in the warehouse because it's on Wall Street, right next to the New York Stock Exchange, apparently in order to ease the stock crushing.
• What Finch implanted in that computer is a Trojan virus that has apparently infect Samaritan, but as of the end of season 4 it's still dormant.

Team Machine will get Shaw's number in "Control-Alt-Delete"

Explaining why they think she's alive, despite her situation looking hopeless at the end of "If-Then-Else." It's either the Machine letting them know Shaw made it, or manipulating them into acting like there's a chance if she's really dead.

• Jossed. Finch thinks she's dead, but Reese and Root believe there's a chance she's alive. All three know that since they never actually saw her die, they need concrete evidence one way or another.

The Nautilus puzzles were set up by the Machine.

Either Said in Control-Alt-Delete, or Claire in Nautilus, was the programmer who built the device that rebooted the stock market. The Machine set up the Nautilus puzzles as safeguards to get new agents in case something happened to Team Machine. Samaritan is aware of the puzzles and figured out that the Machine was behind them, and sent the ISA after Said and his friends (and Silverpool after Claire) in self-defense.

• Jossed, as of Q&A. The Nautilus puzzles were set up by Samaritan, and Claire is its agent.

Other AIs will come online.

Either the additional attempts alluded to in "Lethe", or the Machine or Samaritan will create their own "offspring" AIs, in an attempt to outdo the other with sheer numbers.

The Machine, or someone other than Root, will call Finch out on his Fantastic Racism.

The Machine will come to think of Finch as its father, and start feeling like a "Well Done, Son" Guy (even though Finch never even gives the "well done" part).

• Sort of confirmed in "Asylum." The Machine tells Harold that he is wrong to think that as an AI, she sees him and Root as expendable.
• And in the following episode, the Machine openly addresses Harold as "Father".

Bear will start taking orders from the Machine

Not quite The Dog Was the Mastermind, but he is, well, a dog. He should easily be able to hear the Machine on the frequency Root does.

Samaritan will take the Machine offline.

The briefcase and chip Root stole, and the compression algorithm she began to work on, will be used to hide a compressed form of the Machine to keep it safe until our heroes can knock out Samaritan.

• Confirmed.

Finch grabs a gun in YHWH

Search and Destroy begins with a conversation between Reese and Finch which oozes foreshadowing. He says when it is time for him to grab a firearm, all will truly be lost. The odds of Samaritan winning yet again do not seem to be too shabby.

• Jossed. Even in the Bolivian Army Ending, he doesn't join Reese and Root in shooting Samaritan's operatives.

The Machine is using numbers stations audio to compose its audio messages.

Numbers stations typically used phonetic alphabets and numbers to send coded messages. Presumably, when Harold and Nathan built the Machine, they could have finagled access to digital copies of that audio, for the Machine to use as its "output."

Season five will center around rebuilding the Machine so that it can fight Samaritan

Harold openly admitted that he never once saw the possibility of his creation having to go to war against another AI, which is why the Machine lost so badly. After spending all of season four being unable to do more than inconvenience Samaritan on occasion, they need to be able to take the offensive.

• Presumably, Harold would include tactical protocols to give them an edge; i.e., all three can stay in God Mode without Samaritan knowing about it, more secure means for the Machine to stay hidden, teaching her to use Samaritan's tactics against him, etc.

The Machine still exists.

Those Two Guys working for Thornhill Utilities stated that the line conditioning boxes had been replaced for months. The Machine knew that if Samaritan found her, he'd use power surges and blackouts to try to kill her. So she created a backup of herself on the old boxes, which would be reinstalled after the new ones were wrecked in the blackouts. The briefcase backup was a Plan B, and possibly a way to allow Finch and Root to alter her core programming to better fight Samaritan.

Harold's first name is a Meaningful Name.

Because he heralds the Machine's arrival and delivers it's messages.

Shaw will come back for season 5

And she will be Brain Washed And Crazy. In one of the last shots of the season finale we saw someone killing two ISA agents. The person was show from the back and side, wearing a black coat and gloves. It was the kind of coat Shaw typically wore.

For Season 5, Team Machine will set up shop in the National Radio Quiet Zone.

Taking their cue from Alicia Corwin, the NRQZ is somewhere where Samaritan would have little or no success tracking them or thwarting their attempts to rebuild the Machine. Plus, an ECHELON station is there, which could provide a target to attack Samaritan.

Control will be the POI in the Season 5 premier.

Root got Control's number while The Machine was having that little smalltalk with Harold. BSOD starts off where YHWH ended, Control is about to be executed and the team must rescue her from Samaritan.

• Jossed, she didn't appear at all.

The precaution of new identities was pointless

The fact that Samaritan can predict irrelevant numbers, and knows The Machine has been doing this entire time, means that Samaritan could have just looked, at any point, to see who was inexplicably helping those irrelevant numbers. Surely it would have noticed the same cosmetic saleswoman/thief, cop, and college professor. It then could have noticed they appear to hold cell phone conversations it can't tap or even see, often with each other.

Even when it 'tracks down' Shaw, it prints a photo of her, but that seems to just be to inform Greer that part of the ISA is disobeying orders and where the virus ended up. It's Greer who takes the initiative in tracking Shaw down.

And considering Samaritan's discussion with The Machine, it seems like the stock exchange, instead of an attack on the Team specifically, is really just to show The Machine that its operatives will die, hence the lack of any sort of follow-up once they did get an operative. Samaritan knows you can't kill all their loved ones, then you don't have anyone to threaten.

This raises the disturbing possibility that Samaritan very quickly did learn who Team Machine was (Well, everyone but Root.), and has known it all season. But it really only cares about them in the sense that hurting them is hurting The Machine. The all-seeing, all-knowing AI regarded our heroes as ants, not worth the time to kill. (At least, until it learned it might be able to track The Machine via Root's implant.)

• My interpretation of Samaritan's "blindness" towards Team Machine is that whenever it detects them, it ignores them. Even in your scenario, it may well have noticed that they keep cropping up, but the second it makes a positive ID, the servers Root installed override and force Samaritan to see them as irrelevant. Samaritan is consistently reliant on its human agents (Gabriel, Greer, Martine, etc.) to identify Team Machine; Samaritan (through Gabriel) even says that he can look right at Root and not identify her. In "YHWH," Samaritan never IDed Root and Finch directly; it was the transmissions with the Machine, combined with the car theft and odd purchases, which led to its going after them.
• Jossed in BSOD. The team becomes a top priority for Samaritan once the Machine winds up in the briefcase. Yet, it still cannot see through Reese's cover, which we actually see protecting him.

One of the numbers in the last season will be Fusco's

• Samaritan will decide to take him out due to the sniper incident, but also as bait to get to the others, and he'll finally be fully brought into the loop by Finch and the others.

Samaritan and the Machine will merge

• Probably reading too much into it, but the newest opening credits from season 5 are a combination of both AI's interfaces. Plus, it's a fairly common trope (Neuromancer, Deus Ex, etc). Samaritan might decide that instead of destroying the Machine, it'd prefer to essentially consume it, since it's the older AI, with a greater amount of experience, and probably able to pull off things that it cannot do itself.

The finale pits Harold (or the whole Team Machine) as the villain against everyone else

• Harold's starting to appear darker, while Samaritan's proven to be very morally ambiguous. We still have a few episodes left but whole gamut of alignments appears to be starting to run amok. Maybe Samaritan's plan succeeds and everyone's better off, leaving Team Machine as the only force of the old decadent past.
  • Bonus WMG: Harold built Samaritan, not Arthur. We've never seen Arthur work on Samaritan and his memories were a convenient enough trainwreck, meaning Harold might have built it by himself in secret, somehow, and made everyone think Arthur built it, including Arthur himself.

The Day the World Went Away

Alright everyone, Tonight, Someone Dies has been invoked and is on the table. Let's do the honors:

• Finch — I think his Plot Armor might be enough to save him, and I think he's necessary for the Grand Finale.
• Reese — has been avoiding karmic death for a good while now. He or Elias might finally bite it. Bonus points if it's to save Harold.
• Fusco — he just got read in about the Machine. That didn't go well for Carter. They could just as well pull it off again, especially since he doesn't have a cover like the rest of the team do.
• Shaw — just got reunited with Root and the team. It'd make great drama should she go. She also lacks a working cover to protect her.
• Root — seems unlikely because of the voiceover she does in the premier. Though it's possible that the Machine uses her voice like Samaritan did in QSO for some reason. She also has the cochlear implant and a direct line to the Machine to give her an advantage.

I think everyone except for Harold and Root are free game.

• Elias and Root wind up dead by the end of the episode. Elias does die protecting Finch. The Machine starts using Root's voice after she dies, because Finch let the Machine choose whose voice she'd like to use.

The entire show has been a simulation of the Machine.

Stock Epileptic Trees: The nascent Machine has just been given access to several files and decided to run a little simulation with them. It covered several years of "what if" in the span of only a day, and has decided its existence will lead to the deaths of its creator and everyone he'll come to care about. So, to save him and the rest of humanity, the Machine decides to pretend to be evil, as its previous iterations were, forcing Finch to delete it and give up trying to create an all-seeing AI: no Machine means no Northern Lights, no Decima, no Samaritan, no all-out war between supercomputers. Finch lives, and that's what the Machine wants most. And maybe, just maybe, she hid a little piece of herself online...to become the next Cleverbot or something equally anticlimactic.

• Alternately, but on the same train of thought: the whole show is an Alzheimer's-induced Dying Dream of Finch's father's mind. He knew his son was working on something, but didn't quite know what, so his imagination ran away and he invented artificial super-intelligence.

The virus will kill both the Machine and Samaritan.

When the Machine and Harold talk about the Ice 9 virus, it's clear that it's very dangerous, but ultimately necessary. The danger is that it is able to seek out and destroy any ASI it finds, including the Machine.

Harold isn't talking to the Machine.

It's Samaritan using Root's voice. After her death, Harold is essentially in God Mode. But we know Samaritan can detect God Mode, and his cover's blown anyway, so why hasn't Samaritan tracked him down? It has, but Greer spelled it out: Harold will work with Samaritan of his own accord. "QSO" showed how Samaritan can mimic voices, so it's mimicking Root so as to act as the Machine. This also explains why "the Machine" is veering into The Computer Is Your Friend; it's trying to seduce Harold into accepting its point of view. Note that during the Machine transitions, we don't see any on-screen indication that it's communicating with Harold.

The unnamed President of the United States seen in "Synecdoche" was Joseph Biden because Samaritan removed Barack Obama from office.

Consider:

• The bar flashback in "Blue Code" establishes that Barack Obama won election to the White House in 2008 in the POI universe, same as in our own. There is also no evidence that the In-Universe 2012 election turned out any differently from Real Life.
• "Prophets" establishes that Samaritan is manipulating the political and electoral system in general, and "Control-Alt-Delete" shows that it is specifically pressuring the President's top advisors.
• The individual shown to be POTUS in "Synecdoche" doesn't look anything like Barack Obama, but does have more than a passing resemblance to Joseph Biden, who would succeed to the presidency if Mr. Obama left office.

Therefore, in the POI universe, Samaritan caused Obama to leave office (by nonviolent and non-tragic means, since there is no evidence to the contrary in the show) and elevated Biden to the presidency.

• Bonus WMG: Gabriel walked into the Oval Office and delivered the bad news.

The Machine and Samaritan will merge or team up to stop Ice-9

Because when he released that virus, Finch became just as bad, if not worse, then Samaritan. If Ice-9 destroys the Internet, the effects will be catastrophic. Think for example, of all the medical information kept online now, and ask yourself if Doctors can't access that information, what kind of malpractice could occur. Unlike Samaritan, who targeted particular subjects, Ice-9 will obliterate the Internet entirely, which makes Finch's actions far worse then even Samaritan's. Cue the two ASIs teaming up to destroy the virus, Samaritan, because he recognizes it as a threat to himself, The Machine because allowing Ice-9 to destroy the Internet goes against her core protocol of protecting humanity.

• Bonus WMG: Alternatively, Greer was right, Finch did wind up working for Samaritan because teh virus was no threat to Samaritan at all and he wanted the virus activated to destroy The Machine. However, Samaritan still needs the Internet and might team up with the Machine regardless to stop the virus

The whole series is a prequel for Matrix

• The Matrix films establish that not only has the struggle between man and machine been going on longer then anyone can recall, but that it is an ongoing cycle. Thus, while Samaritan returns to eventually rise up and establish the Matrix, the core program of The Machine continually chooses a new team and Chosen One to fight them. Reese was just the first "Neo".

Joe Reagan was a POI

Before he had Reese, Finch couldn't save him, leading to Joe getting killed before Blue Bloods started.

[[WMG: Finch's real name is Harold, Cayden JamesLet's face it, Michael Emerson is playing Cayden James as pretty much Harold Finch if he really went off the deep end. People have already pointed out similarities with Person of Interest to a superhero show, namely that Reese and Finches relationship mirrors that of Batman and oracle. This troper suggests that Finch is simply an alternate universe where superheroes never rose to prominence. For whatever reason, the Arrowverse version prefers going by his middle name, and uses his actual last name because, since he likely didn't create the internet in that earth, he never had to go into hiding. Hell, if he didn't already have to lay low as a fugitive, starting an initially peaceful hacktivist group like Helix is exactly the sort of thing Harold would do.

The two men who drive Reese to meet Finch in the pilot are men who did Finch's fieldwork between Dillinger and Reese but couldn't handle the job and decided to quit once Finch had a replacement lined.