Season 2, Episode 17:
Proteus
The Machine gives Finch and Reese the numbers of six individuals who have all vanished without a trace from various cities throughout the country, and who may have all been victims of a serial killer who likes to take over the lives of the people he kills. Their investigation leads them to Owen Island, where they are forced to wait out a severe storm with a group of locals and unknowns... one of whom may be the killer they're searching for.
Tropes present in this episode include:
- Big Damn Heroes: Carter and Cal play this at the end.
- Blind Without Them: Finch can't tell for a moment who saved him, as the killer removed his glasses. Or at least that's what he wants Carter to think; given that the killer wore his glasses without squinting and he didn't seem to have any trouble seeing until she showed up, there's a decent chance he's faking.
- Brick Joke: Reese knocks out the fisherman, drags him off for disposal while grumbling about his lot, then gets hit on the head. Then the whole process repeats, with Reese and the fisherman in swapped roles.
- Bulletproof Vest: Saves the murderers life the first time he's shot. The second time... not so much.
- Can't Kill You, Still Need You: The killer needs Finch to fly him off the island first. But when Finch gives his "The Reason You Suck" Speech, he decides to kill him then and there.
- Closed Circle
- Conveniently Timed Attack from Behind: As noted by Finch when Carter saves his life. Moments later, Carter and Finch have their lives saved by Cal.
- Conviction by Counterfactual Clue: Reese says the K-Bar the deputy was stabbed with isn't something you can get in a bait and tackle store, as it's a Marine Corps knife. He might have mentioned that any military surplus store would have one, not to mention they're readily available online. It does however scare the man into admitting he's a Marine deserter and the knife is his, but he denies using it to murder anyone.
- Dangerous Deserter: Apparently the first suspect, but averted.
- Detective Mole: The Serial Killer killed the FBI agent tracking him down and took his place.
- Disposing of a Body: Finch (with the help of Bear) finds the charred teeth of a previous victim in a furnace. The killer later complains of the difficulty of disposing of the teeth.
- Dramatic Thunder: A more subtle version.
- Drives Like Crazy: Cal loses his temper when Carter suggests he might be a Dirty Cop, and puts his foot down while driving through a storm. When he realises what's happening and stops, Carter has her hand on her gun.
- Everyone Is a Suspect: Well considering they have no idea who they're looking for, yeah.
- Explain, Explain... Oh, Crap!Finch: He was posing as an FBI agent. He was really quite good at it; he had a badge and a gun and... body armor...
- Foreshadowing: Finch and Reese both know something is wrong with The Machine because it went three days without giving them a new number. There were also a large number of blue-screens visible during the shots where the Machine pans from one scene to the next.
- At the start of the episode, Finch and Reese come out of a theatre showing Rashomon and Rain People.
- Four Eyes, Zero Soul
- Frame-Up: The marine deserter's knife is used to kill the deputy.
- Hidden Depths: Finch can fly a plane. Also doubles as an Offscreen Moment of Awesome because he quite successfully landed his seaplane in the middle of the town.
- Hostile Weather: The storm that traps them on the island with the Serial Killer.
- I Need a Freaking Drink: Finch doesn't turn down a Quick Nip when it's offered. After the crisis is over, Cal shares a drink with Carter, noting that any police station has a bottle of booze somewhere.
- If I Do Not Return: Reese tells the FBI guy to get the others to safety if he doesn't come back from chasing the fisherman.
- Kill and Replace: Not only the killer's M.O., but something he's compelled to do. When he says he'll stop doing it when he finds the perfect identity that fits him, Finch knows he never will.
- The Killer Was Left-Handed: Cal spots the person on a video tape isn't the same man who came back the next day because he used his left hand to unlock the door.
- Lie Detector: Finch rigs up an improvised version with seimograph equipment, measuring the micro-tremors from the interviewees hands resting on the table.
- Lightning Reveal: Well that was freaky.
- Note: You can see the guy behind Finch near the start of the scene, nearly invisible in the darkness — it's just that if you're not looking for him, the lightning is the first time you know he's there.
- Lights Off, Somebody Dies: The power goes out just as Carter is getting through on the radio. Reese goes to reconnect the generator, only to find the radio trashed and the deputy murdered.
- Noodle Incident: Reese noted that this was not the first time someone shot at him with a spear gun.
- "Not So Different" Remark: The murderer points out that he and Finch are a lot alike in their approach to assuming a false identity and hiding who they really are.
- Oh, Crap!: When Finch realized that the Killer had a Bulletproof Vest. And earlier when Finch studies the lie detector printouts and realises he'd ignored the reactions of the FBI agent.
- O.O.C. Is Serious Business: The Machine is visibly slowing down, and Finch worries that whatever virus Stanton uploaded may be the cause.
- Ooh, Me Accent's Slipping: In-Universe example. The serial killer's accent is all over the place during his climatic scene with Finch, including a truly chilling moment when he reveals that he plans to assume Harold's identity and then he repeats Finch's previous question multiple times so that he can adopt his speech pattern.
- Punk in the Trunk: Reese is about to do his usual thing with the fisherman, only to find someone already in the trunk, the FBI agent he's supposedly working with.
- The Radio Dies First / Cell Phones Are Useless: The bad weather first interferes with Reese and Finch's cell phone connection, and then later the murderer destroys the radio at the police station after Carter tries to contact them with information about his identity.
- Reasonable Authority Figure: The local sheriff is pretty accommodating to Reese and the FBI agent, while providing some theories of her own.
- Red Herring: Several. The killer disposes of the people he replaces by burning their bodies after pulling out their teeth, two of the suspects are dental hygienists. One man owns a military grade knife that is used in a killing. A third is a fisherman who keeps trying to get to his boat in the middle of a storm. A fourth is a developer checking on his project who the townspeople explicitly note that they haven't met in person yet. The dental hygienists are just dental hygienists. The man with the knife is a deserter from the Marine Corps. The fisherman is a drug smuggler. The developer is the real developer. None of them are the killer.
- Stealth Pun: the fisherman is a Red Herring.
- Serial Killer: The bad guy of the week.
- Shut Up, Hannibal!: Finch delivers a nice one while talking with the murderer.
- Shout-Out: Harold Finch was totally channeling Benjamin Linus during his confrontation with the murderer."You'll never get off the island."
- Spoiler Opening: You probably won't notice it on the first time, but usual Couch Gag shows two different scenes - one with today's number, other with Reese entering the garage. This is his scene with today's killer, but we don't know it yet.
- A Storm Is Coming : At the end of the episode they have this conversation.Reese: At least the storm is passing.Finch: No, Mr. Reese, I have a feeling that it's just beginning.
- That's What I Would Do: Finch notes that the killer would erase his previous identity after he'd finished using it, because that's what he does.
- Umbrella of Togetherness:
Finch and Reese going out of the cinema. - Whole-Plot Reference/Shout-Out: And Then There Were None — the name of the island, Owen Island to the character that invited the guests in the Agatha Christie story, UN Owen(Unknown). The nature of the storm causing everyone to be trapped is also similar. It also takes the idea of a serial killer taking over victims' identities from Taking Lives.
