Fridge / Infinity Train

As a Moments subpage, all spoilers are unmarked as per policy. You Have Been Warned.

Fridge Brilliance

General/Multiple Books

• The half infinity signs seen in the opening logo and on the train could be a nod towards One-One.
• Turtles don't seem like a significant Animal Motif at first. At least until you remember the phrase "Turtles all the way down" which talks about how the Earth is supported by the back of a large turtle who is supported by a larger turtle for an infinite amount.
• The train's goal is to bring the people onboard to a healthier mindset. It's a train of thought.
  • One would think that a train that only brings you back to where you started via the long, long way around would be pretty lousy... but in truth, you have to remember: It's about the journey, not the destination.
  • Passengers and denizens can't leave the train until they've worked through their personal issues. If they don't or try to escape, they either fail and end up back on the train, or die broken and unfulfilled. Many cars a passenger might encounter will trap the passenger in a situation where they literally can do nothing except the action required to unlock the exit doors. This is called Railroading.
• One-One’s two personalities may seem like just a fun gag, but considering how the train's true role is essentially a therapeutic, it might actually represent how passengers are supposed to come out of the train: happy and cheerful, but not repressing their negative feelings and being open when they aren’t happy.
• The train cars that passengers begin their journeys in aren't arbitrary. Tulip woke up in The Snow Car because she boarded the train in a snowy field. Jesse woke up in The Hill Car because he boarded the train near the hill he got his brother injured on. And while Ryan and Min-Gi definitely weren't near any icebergs when they boarded the train, they were heading to a big city, which turns out to have been the default state of The Iceberg Car before Kez messed with it. Why would the train do this? Well, by letting passengers wake up in an environment similar to where they would naturally expect themselves to be based on their last memory, they don't instantly devolve into terror and panic, allowing them to better acclimate to the train than if they woke up in a place that was completely unfamiliar. This also leaves them calm enough to receive potential guidance or help from any nearby denizens, as opposed to immediately run screaming in the other direction.
  • This would also explain why the Mall Car is the Apex base of operations. Grace was taken by the Train after she was caught stealing from a mall.
• The series ending with a prequel, which not intentional, is still brilliantly fitting. Book 4 doesn't take the time to explain concepts like numbers or tapes, because it assumes you've seen the other seasons. Yet at the same time, Amelia's takeover of the train happens during Book 4's events, setting up the circumstances for Book 1. The nature of the show itself has become cyclical, or in other words, infinite.

Book 1

• Tulip is named after the "perennial flower" because she recovered from nearly dying as a baby, and the subtitle of the season starring her is The Perennial Child. One definition of the word perennial is "lasting or existing for a long or apparently infinite time; enduring or continually recurring."
  • Alternatively, the Perennial Child can also refer to Amelia, who would rather live in a world where Alrick was alive than move on from the loss.
• In "The Grid Car", One-One guesses his mother may be large or "small, like a nurturing bagel." This makes a lot more sense once Tulip and company reach the engine where we discover One-One was the Conductor preceding the show's main antagonist. His mother is the train's large control panel, and he fits into a small, circular slot on the dashboard, much like the Orbs we'd seen earlier.
  • A huge hint about Amelia being the Conductor comes from Glad-One's first question, "Are you my mum?" Mum is what someone British would say and Amelia is from England!
• Seeing another passenger apparently atomized by an energy vortex reaching into the train, Tulip asks One-One what happened to him. Sad-One responds, “You’re in kind of a bad place right now.” It’s assumed he’s referring to her current situation, but he’s actually referring to her mental state, which turns out to be key in summoning those vortexes.
• In "The Beach Car", One-One tells Tulip that when her number reaches zero, she’ll be gone forever. This wasn’t a Deadly Euphemism; once the passengers overcome their trauma, they get to leave the train a better person and presumably never come back.
  • More importantly it's Glad-One who cheerfully states that Tulip is gone forever should that number drop to 0. Since One-One is the Conductor — whose job is to help people fix what's wrong with them so they can go home — of course he'd state that being "gone forever" as a happy thing.
• The Steward destroying many of The Cat's things becomes this later on, turning from a lax punishment to an expression of spite. After all, the train made all of that, but it can't give The Conductor the one thing she truly wants: her past with Alrick.
• In the Corgi Car, the Steward could have killed them all, but instead leaves... after One-One sings the command tone that the conductor uses to control the Steward. Turns into Fridge Humor when you remember One-One said the Steward should go dance in the Monster Mash car...
• In "The Unfinished Car", the turtle king's intro is oddly similar to Atticus's, and if you look closely at the turtle guards' pauldrons, they have corgis on them. As we later learn, they are recycled from The Corgi Car's data.
• In "The Unfinished Car", One-One takes a sharp turn into O.O.C. Is Serious Business when he insists on trying to fix it, despite the denizens being quite happy with the way it is. The reason being is because he's the actual conductor for the train, and he would want the cars to be completed, not unfinished and disarrayed as Amelia left some.
  • Fridge-Tear Jerker: His trying to fix the car is very parallel to Tulip's view on her parents' divorce, as in "bargaining". Perhaps One-One trying to fix the car is his way of thinking that Amelia might not have usurped him as the Conductor if only he had carried out her wishes of making an Alrick car, or if he hadn't even divulged about how the Train can create anything. Thankfully, Tulip is able to convince One-One that there's nothing to fix.
• Why does The Unfinished Car has such weird gravity? Think about it: the car is based off of Amelia's life with her husband, Alrick. When he died, her entire world turned upside-down.
• In "The Chrome Car", Mirror!One-One is the one who stated that he called up the Mirror Police, much to MT's anger. Of course as One-One is the true conductor of the Train, it would make sense that he — or at least the reflection that has all his memories — would immediately know what MT was planning and placed immediate action to grind her into find dust.
• The Conductor seems to wear a mysterious robe, though some find it strangely dorky for her to be wearing it for seemingly no good reason. That's because it is dorky; Amelia's emulating her late fiancé Alrick's playful Cloud Cuckoolander style of dress, as part of her way of not forgetting him.
  • Even better, when does one usually wear black? When in mourning. And Amelia has done nothing but mourn for thirty years.
• There's very subtle Foreshadowing and reinforcement of the show's main theme in "The Ball Pit Car." After Tulip sees Atticus turned into a Ghom, the Conductor mocking tells her "No more tears". But One-One states "It's okay to cry." On the "reinforcing themes" side of things, it's a reflection of how one ultimately needs to accept that an traumatic event happened ("It's okay to cry") rather than ignore it or live in denial ("No more tears"). On the foreshadowing side, it's another Rewatch Bonus hint that One-One is the true Conductor of the train. The Train is supposed to help people going through trauma after all, and his supportive action makes far more sense than Amelia's dismissive one.
  • It's also a case of Irony: The Conductor is a human inside a robotic shell while One-One, the true Conductor is a robot. The human, the emotional one, doesn't want Tulip to grow while the robot, usually the emotionless one, is the one that comforts Tulip.
• In "The Past Car" Amelia is shown manipulating the phone network by playing a specific tone on her flute. In her guise as the Conductor, she uses a similar method to issue commands to the Steward ^note (incidentally using the same tones as the show's theme tune). This is likely also the way she originally wrested control of the Steward from One-One and removed him from the engine.
  • Also, a conductor is a term for trains and for music.
• After "The Past Car", many of the cars that are mentioned or seen can now be viewed as foreshadowing. The Crystal Car that only opens its door if you sing a song close to you? Amelia was shown building a crystal radio as a child. The pilot-only Fart Car? It comes from the memory of Amelia's teacher sitting on a whoopee cushion.
• Why would Tulip retort about having a pipe in her bag by calling it a "donut holer"? Yeah, it's a fun Brick Joke, but really think about it. Who first called said pipe a donut holer? The Cat. Who was the Steward trying to kill aside from Tulip? The Cat. Tulip is essentially telling the Conductor that this attack is for harming The Cat, who Tulip now sees as a friend.
• At the very end, both of Tulip's parents are not only Amicable Exes, but also seem to have gotten the scheduling down. Given that the show states that it was 7 months later, but it's already time for camp again (which is an annual thing) it implies that Tulip was gone for 5 months. The two most likely went through hell looking for her, and slowly came to terms with their own faults and worked them through.
• Tulip is named after a flower, and her father's nickname for her is "bud."

Book 2

• Jesse's character as The Ditherer actually compliments MT. He reflects back what other people say.
• The Cat has an utter hatred of Grace and her cult, but why? Well in "The Mall Car", the group shatters the cubes that belong to the resident of that one because there was "nothing salvageable" and they were shown destroying things in "The Lucky Cat Car". Given how The Cat values all of the stuff she collects, perhaps Grace entered that car and destroyed everything there just because she could (whereas the Conductor did it to strike fear in The Cat's heart).
• The pod's passengers arrive in may look familiar to some viewers. Why is that? Look back at Amelia’s robot suit from when she was posing as the conductor. This also fits into the theme of the show since she modified her pod into her mech suit’s head. She literally refused to come out of her shell and face her problems.
• Sashay and the residents of the Runway Car being Easily Impressed make sense considering that they are on a train designed to help people: the car exists to promote body positivity and self-confidence for the passengers! This is especially relevant because Jesse's lack of confidence is a major reason for him being on the train in the first place.
• When Grace opens the hand mirror to summon Mace and Sieve, one at first wonders how they got out of the Toad Car, until you realize that the Toad/Terrence is now charging people to kick him. Given that Grace was in disguise while competing to exit the car, chances are she paid to kick him just because she could, which would have released them from the car, as it is never established that the Toad has to be IN the car in order for kicking him to open it.
• MT attempts to take another passenger's number by placing her hand in the path of the grafting laser, but the laser just passes through her hand and onto the passenger's. It makes sense that the laser was designed to bypass anything obscuring a passenger's hand when it grafts the number because the train would have to accommodate for anything covering the palm to ensure the skin itself is marked. Case in point, Tulip was wearing gloves when she entered the train, which resulted in her not even noticing her hand was marked until taking her glove off one car later.
• MT spends the entire season rejecting her status as a reflection and wanting to be her own person. It is appropriate that the only way she is able to escape to the normal world and gain her freedom is by reflecting Jesse's number.
• Why wasn't Simon raiding "The Lucky Cat Car"? Because he didn't want to have an encounter with The Cat as it'll only bring up horrible memories of her leaving him behind.
• Jesse's return to the Infinity Train stems from a problem having to do with the Infinity Train, a problem the Infinity Train cannot solve. How does the Infinity Train's system represent this? With imaginary numbers and variables, as opposed to the whole numbers that most passengers possess. However, when MT uses her chrome hand to copy the number on Jesse's hand, she is creating a reflection of that number, an opposite version of whatever amount Jesse has. And sometimes, the only thing you can be certain about a variable in a math equation is that the variable, when it has its opposite value added in, equals zero.
• In the first Documentary short, the Green Car has a hole shaped like a deer's front, with Glad-One remarking it was an unusually specific shape but nothing to worry about and Sad-One saying "That's what they want you to think". Most likely, Allan Dracula had been there and made said hole.

Book 3

• The terms "null" and "void" are used as fantastic slurs throughout Book 3 (although the latter is used to denote a human who sympathizes with residents of the train or "nulls" and only is used in the finale). Both are key terms in programming. "Null" denotes that an object/pointer has no "address" or "value", indicating how to the Apex, denizens are generally considered worthless. "Void" is used as a parameter in functions or methods, either as an input parameter (or argument), or output (or return type), indicating that it either does not actually take input or produce output, reflecting how Simon has been trying to get Grace to respond to him, but she's been shutting him out and not responding the way he wants, a sentiment which climaxes in the finale.
• Laurent is a french name, Simon can speak french and the french speaking cat was once his Parental Substitute.
• Hazel, as a colour, is a shade between brown and green. Hazel, as a person, has brown skin and in her turtle form she has green skin. Hazel has always been a mix of brown and green, we just didn't realize it was literal.
• Whilst Simon's Mysterious Past is a Riddle for the Ages, he shows an unusual knowledge of funerals in episode 6, far moreso then someone whom lost with the "real" world at age 10, should have. Given his abandonment issues and there is nothing for him off the train, it's likely Simon lost a family member important to him and that may have been the reason he went on the train to begin with.
• Amelia taking in Hazel is sweeter than it appears at the time. She reveals that Hazel was one of her failed attempts to recreate Alrick, which essentially makes Hazel her daughter, and possibly Alrick's as well. Hazel, on learning this, says that she would rather stay with Amelia than with Grace and Simon because Amelia showed more caring and compassion than the teens did, as well as a sense of responsibility (though this may not be much of an accomplishment given the Manchild status of both teens). She also affirms that Amelia doesn't need to be a mother to her, which convinces Amelia that Hazel can stay. Despite herself, Amelia looks touched and surprised that a child wants to be with her, and it provides hope that she can find joy again after Alrick's death.
• The origami birds in the final two episodes. Cranes are seen as a symbol of good health and luck. Folding a 1000 Origami Cranes is said to grant one a wish; as such, the act of folding origami cranes is synonymous with keeping hope during challenging times. Grace re-folding the birds to heal them, them saving her in return later on, and one of them staying with her at the very end, are all signs that she has indeed changed as a person and will work hard to redeem herself, no matter how challenging that task might be.
• Why doesn't the Train or One-One stop Grace and the Apex? There are two reasons:
  •  One-One for all his Character Development is still distant from the passengers, with Tulip being the exception thanks to Amelia's takeover. They haven't seen the devastation firsthand that Grace brought, and seem to think that if she wants to terrorize the denizens along with the rest of the Apex, that's her problem. One-One's explanatory videos should have been the first clue that they were barking up the wrong tree. If not? The denizens have to bear the repercussions. 
  • Second, redemption and solving your problems is a choice: if you were told what to do and how to act as well as the consequences for if you fail, then your actions would have no weight to them. That is the moral deserts issue, something that came up in other shows. You have to decide to turn around and change for yourself, not because someone tells you to, as we saw when Jesse's number went down after he stopped listening to MT and found his own solution to problems. Grace establishes that she doesn't want to leave the train: she and Simon want to conquer it. If another passenger chooses to leave or a denizen escapes her wrath? Fine. There are other denizens to wheel, and more passengers to induct or "rescue" in her mind. Hazel was the first denizen that escaped Grace's control and conquering mindset, bluntly telling her that Grace was wrong; she was not a child whose number could go up, especially when they find out she's a turtle hybrid. She didn't fit in the previously-established dichotomy. What's more, Hazel asserts that the false Conductor is a better parental figure without even wanting to be one, because unlike Grace, Amelia has no desire to kill denizens For the Evulz. Even then, Grace wasn't ready to make that final active choice.
• Grace's use of lipstick for the facial markings is kind of silly, until the flashback of the "Origami Car" reveals that she tried to doll herself up with her mother's makeup. Her mother was also wearing classy gloves too. In a way, she's trying to be the antithesis of her neglectful controlling mother (by wearing shirts and pants instead of fancy dresses and sunhats)...but ultimately, she's not so different as she's controlling what the Apex should know about by making them believe everything she says, even if it's not 100% accurate.
  • Fittingly the last thing Grace saw before the Train came to her was her father trying to take control of the situation and reject that his daughter was a thief. What does she do with Simon? She takes control of the situation and reject the idea that she has no clue what the Train is about. In a sense, she's no better than both of her parents.
• Simon's death (gruesome as it may be) may be shocking when you first see it, it was subtly foreshadowed earlier in the season in the episode "The Jungle Car". A butterfly landed on a napping Simon's nose and butterflies are associated with life, transformation, hope and change. Death has also been foreshadowed by the use of moths which are similar to one another. Butterflies and Moths belong to the same insect family so in hindsight, anyone could've seen it coming if the butterfly was noticed.
• The Tragedy Mask being the Sole Survivor of the Musical Car raid foreshadows Grace being the only survivor of the protagonists? How, you may ask? Because Grace wore a mask: physically (the gold mask with the Conductor's wavelength) and metaphorically (she pretends she's the one who holds all the clues to hide that she doesn't know). It's fitting that she wore the mask during the raid on the Unfinished Car but after she and Simon are separated from the Apex, she must work on removing both of her masks and reveal that underneath that haughty facade is a broken woman who only wants love and doesn't care who she has to trample on to get it.
  • Moreover, a tragedy in Greek terms focuses on a hero with a Fatal Flaw who loses everything for their dream. Grace's flaws of pride and desires to be loved made her lose everything: she loses her innocence over how she's the expert. She loses her friend, Hazel and Tuba. She ends up with nothing more than the giant number representing all of her sins and nearly loses her life if she didn't have a change of heart with the origami birds.
• The Musical Car's destruction on everything being set on fire and turns to ash foreshadow the end of the Apex. Grace's actions made her burn bridges with everyone and Simon ends up turned into ashes by the Ghom. Plus, after the group is done with their destruction, they decide to take a bow. The cast of a theatrical performance does this when it's the end. While this is symbolic of how they ended their raid on a bright and cheery car, it also signals that this is the last time they'll ever be truly together. By "The New Apex", there is no more of the old Apex due to the fallout between Grace and Simon and the truth that they've been going on these pointless crusades for nothing.
• Simon's Karmic Death is meaningful on two levels. Sure, the train's wheels could easily be considered just desserts after he threw so many denizens into them. But, as Hazel said earlier, he didn't come up with the idea to wheel denizens on his own- Grace led him into it, and so the redeemed Grace saves him from the wheels, symbolically 'undoing' her mistake and giving him a chance to move on as she had. By rejecting her genuinely altruistic attempt to save him, he also 'undoes' Grace's act of saving him, so he dies to the Ghom like he originally would have if she hadn't intervened.

Book 4

• Kez is the only Denizen to directly state the number's purpose, something not done by any of the other companions. Given how Kez's home was Morgan, who had multiple Passengers over countless years, it makes sense for Kez to have much more knowledge on the numbers and the Passengers than most other Denizens.
• After the montage of main character memories, we are introduced to One, in an unsplit state, and Amelia, who has yet to take control of the Train. Both appear to acting fairly stable. It isn't until Amelia commences her takeover that we can assume she harms One in a way that causes a personality split between Glad and Sad One which may reflect her own future, experiencing both manic and depressive states throughout her attempts at creating a world in which she could live out a life with her late fiance.
• One's rather cold personality does explain why Amelia said in Book 3 that One-One only sees his passengers as "ones and zeroes". That may seem strange when you take into account how outgoing and sociable One-One is, especially when his having Amelia read a card that assures the passengers about being on "the growth train" contradicts her statement. But perhaps, she was talking about the One she met all those years ago.

Fridge Horror

General/Multiple Books

• Two of the passengers briefly seen on a computer screen at the end of Book One have numbers above 99,999. What kind of issues did they have to go through? Better yet, what if they didn't have that many issues yet Amelia's machinations caused their numbers to rise like that?
  • We meet these passengers (Grace and Simon) in Book Two, and they're the protagonists of Book Three. Let's just say their numbers weren't that high when they got on the train.
  • Most passenger numbers are three digits or lower, fitting inside the person's palm. Considering that a billion is mere 10-digit number, it's barely enough to loop around the palm to reach the wrist. This implies that Grace and Simon, upon their introduction, have numbers counting in googols (101 digits), while Amelia and moreso Simon by the end of season 3 probably have reached tens, maybe hundreds of googols. Whatever math the train uses to calculate numbers, having most of one's body covered in digits translates to numerical values that are basically inconceivable to humans.
• The idea that those with trauma enter the train and have a number tracking down how many issues they go through. Now consider the various types of people battling depression, divorce, loss of significant others...
  • It also doesn't matter how old you are; if you're going through trauma, the train will pick you up and make you go through its challenges until you're ready to go home.
  • The fact that Amelia was picked up by the train on the roof of her university strongly implies that she went there with the intent of committing suicide.
• We occasionally see incredibly young children listed as passengers. This isn't just Fridge Horror trying to think of kindergartners being on the train in general, much less under the rule of the incredibly unstable Amelia, but because of what it takes to be on the train in the first place. Think of the trauma Tulip and Amelia went going through. Yes, one of these kids' numbers is only 10, but it seems unlikely that was her starting number. Plus, while we now know it isn't a requirement, both Tulip and Amelia had high chances of dying if not picked up by the locomotive; Tulip would have frozen to death in the cold, while Amelia was about to commit suicide. The idea of a little girl going through their parents' divorce, moving experience, probably going through an abusive parent, or the death of a loved one is saddening enough, but what if her trauma placed her in a situation where the only option other than getting on a mysterious train that might kill her was staying in a scenario that would have killed her, leaving her loved ones to worry that she might have been kidnapped, ran away or even killed?
  • Worse, what if she doesn't have loved ones? What if she's an orphan?
• Yes, ultimately the train is well-meaning in that it takes passengers suffering some kind of trauma and forces them to confront their issues if they want to leave. However, due to Year Inside, Hour Outside being averted and the train being a Figure It Out Yourself Sink or Swim Mentor, depending on the passenger, it can take months or even years of people's lives to figure out what the number on their hand even means, much less how that knowledge gets them home. Tulip herself was a runaway who unintentionally left her friends and parents worried sick about her after the train abducted her without a trace, and at one point she's led to believe the number on her hand going down is a bad thing due to One-One's tendency for vague wording. How many passengers end up unable to connect the dots that the number goes down when they're improving emotionally, and/or the number getting to zero is their ticket home? How many other passengers died of old age or were killed while on the train before they could resolve their issues? Or spent years trying to resolve their existing issues, only to get home and find new problems waiting for them due to how much time has passed. After all, it's likely they had loved ones worried sick about them; a passenger could return home only to find out a beloved pet, friend, or loved ones passed away in that time.
  • Luckily, part of this gets addressed in Book 2, where One-One has created a video to explain to new passengers what their number means. But not only does that leave passengers stuck on the obvious following question like Jesse was ("what exactly is the problem the train thinks they have?"), but this also wouldn't necessarily help the passengers who were on the train prior to One-One returning as the conductor, as shown with Simon. Plus, it made clear in Book 4 that the lack of information was a thing even before Amelia took over; a denizen might explain things to you, but good luck finding one that not only knows the details and can explain things coherently, but is also willing to do so. It was only traveling with Tulip that made One-One realize that even the most basic of explanations was even needed. And the train has existed for untold centuries...
  • There's also the fact that, in order to increase the chances of you getting on board, deliberately takes on a form that would entice you, like a fly to a venus fly trap. Tulip got a normal train because that's something she was hoping for, but Amelia got a futuristic alien-like train that her curious engineering mind just had to inspect. And Grace got a full-on royal carriage with a red carpet. Inside a building while her parents were oblivious to this happening no less, meaning there must also be a Perception Filter that prevents anyone other than the chosen passenger from noticing it.
• There's no doubt that others have also attempted to jump off the train and travel through the wasteland like Tulip attempted to do in the first episode, especially since One-One themselves point it out as a potential cause of death in one of the documentary videos. Even if they miraculously figure out a way to deal with all the Ghoms, what even awaits for them out there other than a slow demise? Perhaps a Fate Worse than Death?
• The types of trauma the Infinity Train comes for: protagonists have been picked up because of divorce, mourning/suicide and passivity, but what about people with sociopathic tendencies? What happens if someone with a criminal record stumbles onto there or death row inmates or people who have caused intense suffering like rapists, serial killers, domestic abusers, bullies, etc.? If these people don't figure out how to solve their problems, they'll end up hurting those who actually have tried to move on and make them even worse.
• What if one doesn't want to learn or decrease their number? What does the Train do with those who refuse to grow up or intentionally have their number increase (as in different than Amelia who only wanted to use the train to have Alrick back)? Is the train capable of enacting punishments outside of crawling numbers that go past one's hand? What happens if the number is so big that you die before it ever gets depleted to 0? Are you thrown to the Wastelands? Do you become a fixture on the train? Simon died to a Ghom, but is that the purpose of the creatures or was it just conveniently there to do the deed?
• Due to the fact that many countries and societies don't see any need for therapy, this means that the Train has a infinite amount of people to pick up in order to "fix" their problems and then they are never seen again. How many problems could be solved with just a little bit of therapy or people noticing that's something wrong? How many people are shown regretful for saying something stupid or not saying something sooner?
  • Adding onto this, has it picked up people from times before there was even such a thing as therapy? Take Senua from Hellblade for example; what would happen if the Train picked her up and she had to deal with her schizophrenia when there are no such things as therapists in her time?
  • The cat (Samantha) has stated in book 3 that she hasn't had a vacation in 150 years! Knowinfg that the third season takes place in summer 2020, you can confidently say that the train was around during the 1870s. A time long before modern therapy.
• How many people have committed suicide on the Train because they've lost all hope in figuring out what to do? How many could have been saved if Amelia made instruction videos? Amelia was only saved from suicide because of the Trian, and she repays it by forcefully taking over and presumably denying other suicidal passengers any hopes of confronting their trauams. And she gets away with her crimes and is still kicking after 30 years.
• The protagonists who entered the train were abled, but what happens if the Train happens to pick up someone who's handicapped? The Train is already dangerous to navigate when you're physically capable; how much worse can it be when you're disabled? Or worse, if you had some sort of terminal illness? What about the mere idea of challenge that would end up crippling you anyway if you're very unlucky?
• The series essentially details with the reprecussions of Amelia did during her thirty year reign. While yes, leaving people to struggle on their own and not giving a damn that saving Grace made a cult, one has to remember that this was while she was Conductor. Who knows how many cults and evil groups and other disasters have been caused back when One-One was the cold, apathetic Conductor whom Amelia tried to usurp.
• The Train should be lucky that Amelia only wanted to use it so she can find a way to stay in an illusion where she was with Alrick. What would happen with someone with less morals took over?
• While the Train can provide food, shelter, water, and places to perhaps clean clothes, what if there are special needs people or those who need a specific type of medication to keep them healthy? If a diabetic is stuck there for months on end without insulin in sight, how long would they last?
• What if the person who is picked up has a mental disorder that would give them additional struggles that a neurologically typical person wouldn't have. Will they be trapped on the Train solely for something that's not their fault?

Book 1

• In "The Chrome Car", we learn that reflections are intelligent beings separate from the people that they mirror and that if they become too distinct from them, or try to escape, the Mirror Police will grind them to dust... How many times has what nearly happened to Mirror Tulip happened to someone else? And since Tulip doesn't have a reflection anymore, even when off the train, how is that going to affect her life?
• In "The Ball Pit Car", it's revealed that Tulip has been on the train for months by that point. Since the creators have confirmed that time moves in the regular world the same as where the Infinity Train is, think of how long her parents have likely been looking for her.
• In "The Engine", we learn that Amelia has been trying to create a car based on her old life for years, the Unfinished Car being one of her rejects. How many other malformed cars litter the train?
  • Better yet, how many denizens has she turned into Groms?
  • Both the Unfinished Car and the car that Amelia was working on in "The Engine" are filled with elements from her memories but combined in a nonsensical fashion and with certain small details blown way out of proportion, such as the jelly Alrick was eating at school and the turtles on Amelia's handkerchief. This indicates that her memories are growing more distorted with time. How long does she have until she has no memories of Alrick at all?
• Amelia forces passengers to return to their "seats", seemingly to avoid disturbing her work. But its shown that moving from car to car allows people to interact with more environments and deal with their issues more efficiently. It's possible many passengers never found redemption because of her actions restricting theirs.
• The epilogue has Tulip's father is taking her to camp in autumn: meaning it's the same time the following year. But it takes place seven months after Tulip leaves the train, meaning Year Inside, Hour Outside was averted and Tulip was missing for five months after running away from home in the first episode. We just neatly skipped over all the grief her parents must have gone through, thinking they would never see her again. What's more, Tulip has only one piece of evidence that a magical train stole her away: her Missing Reflection. Otherwise, they'd be demanding explanations for he going missing for that long.
• Given how Mirror!One-One was the one who called the Mirror Police to capture MT, and the fact that One-One is the true Conductor, just how many reflections have tried this tactic to switch places with the person they reflect? How many have been killed? And are there any other people aside from Tulip who have no reflections?

Book 2

• "The Family Tree Car" is kinda creepy if you think about it. Have there been others who were turned to wood from succumbing to hostility and anger? Did they simply become part of the tree's structure? Or worse, did they lose their former identities as they literally got pulled into the feud between the Gillincutties and the Trundleshanks and became "part of the family tree"?
  • Speaking of which; given that the first people MT and Jesse meet were seven Greats, then we're talking about the feud being active for centuries. If that's how long the Infinity Train's been active, how did the people of those times react to somehow being kidnapped by a sentient train so they can confront traumas that they would've had no knowledge of understanding?
• Considering how Marcel and Perry never actually antagonize anyone unless they abandon them, it proves that they spend extremely large periods of time being completely alone in their cars. They only become hostile once anyone tries to leave, who’s to say there’s not several cars with only one denizen who is starved for companionship?
• The Infinity Train can choose people with very minor problems: Jesse's only problem is that he's unable to pick sides, compared to Tulip struggling with her parents' divorce or Amelia dealing with the death of a loved one. How many others like Jesse have been picked up by the Train over similarly small issues?
• The Toad being taken out of the toad car might be good for him, except him being kicked is the only way to open the door, any other passenger who comes across that car is going to be stuck there with no way out.
  • Given One-One's previously shown compulsion to fix cars he deems to be incomplete, it's very possible he's aware of this and can give a new win condition or just remove the car entirely. Or just make a new toad to kick, but let's hope not.
  • It is said by Amelia in the next Book that a car resets after a certain amount of time without any passenger interaction, as to prevent it from being unsolvable .This means that the Toad was either dragged back, or a new one was spawned in as part of the reset process.
• At the end of "The Parasite Car", Perry, who controls people by going in their mouths, is now in a car with lots of food in it. Try not to think too much about that.
• Everything about Grace's cult in "The Mall Car" is full of this: how many children are there, how many children has Grace brainwashed to believe "bigger numbers = stronger", how many parents are searching for these missing children, how long have they been like this, what if they have an epiphany and try to leave the cult to grow, what would Grace do to those who rebel against her authority, how did they even get on the train in the first place...should I continue or have I given you all enough nightmares?
  • Since time runs the same in the Train like in the real world, these kids are going to grow up into sociopathic bullies one day. What happens if they decide to, instead of destroying stuff inside a car, they end up killing the inhabitants due to them unable to see them anymore than "constructs"? What would the Infinity Train have to do in order to maintain stability from the Apex and Grace being the "den-mother" of these cultists? Would it have to pull a Pleasure Island on them as a warning?
  • They likely already have killed some of the train's inhabitants. They were trying to tie down MT and Alan Dracula when Jesse and the others get back. Simon said they were going to throw them under the train's wheels and hoped to have it done before Jesse got back. The completely indifferent way he said it gives the impression Apex has done that to every companion that didn't want to leave their passenger.
  • Picture it: you enter a mysterious train, scared and alone. A denizen befriends you and makes you feel safe and cared for until the Apex finds both of you. You get separated, but when you get back to where you left the denizen they're gone. How easy would it be for the Apex to lie to passengers about being abandoned by their denizens, just to further their cause and drive up numbers?
  • There's a glimmer of hope for the situation in Grace's line, "We just lost another human," from the beginning of "The Wasteland". This implies that others have come to realize that Grace is wrong and broken away from the cult, gaining their exits in the process.
• On that note, Tulip was really lucky that she never ran into the Apex. (It probably helped that she and Grace had polar opposite personalities, where Tulip used the scientific method, as well as having the wisdom to admit when her conclusions were incorrect while Grace just made decisions based on outlandish statements.) She would have spent the whole time questioning their logic, as well as Grace and Simon's authority, potentially angering them. Imagine how anguished she would have been if Grace had gone after One-One and Atticus, trying to wheel them, considering Tulip had a Heroic BSoD when Amelia turned Atticus into a Ghom.
• The old man whose pod MT stole in "The Tape Car" probably had a traumatizing start to his Infinity Train journey. Not only was his pod stolen by a strange metal girl and he got scared off by Alan Dracula's tarantula-form but he's now stuck on top of the train where it is shown that other trains pass by on top and it'd be impossible for him to jump to safety. Even if he managed to get back on the train, he'd probably be apprehensive of what the train offers considering what he had experienced. There's also the fact that it's implied MT threw him out of his pod before he even got his number, meaning he has no way of ever escaping the train and is bound to die on it eventually. Even the show's writers disagree on what happened to this man, with one insisting that he had to have died.

Book 3

• Book 3 confirms that Simon's been on the train since he was at least ten, and Grace has apparently been on as long or even longer, and considering that they both appear to be in their very late teens to early twenties, they have probably been gone for at least a decade, and since we know that time passes the same on the train... Tulip's case was bad enough, and that was just a few months. Do their parents even think that they're alive anymore?
  • With how incredibly neglectful and caught up in their own status and reputation Grace's parents were, they might not have even spent that much time looking for her in the first place.
  • Since Simon has been killed in "The New Apex", any chance of his family ever finding the truth about him is completely gone...
  • Worse Simon's lines indicated he lost a family member to death. He also clearly believes his family didn't care for him and there's nothing off the train for him, thinking that life squatting with Grace on the train is the best life he can possibly have.
  • It's also somewhat horrifying to realise that Grace and Simon have essentially raised themselves with no adults whatsoever. They would have had to deal with all the uncomfortable and weird experiences of growing up and going through puberty without anyone else.
    • And now they're in charge of a bunch of other kids.
  • In season 4, it's revealed that prior to Amelia's takeover, the train simply put it's passengers through a trial from hell and didn't give half a damn about their safety. Jeremy was stuck for 5 years, and he wasn't even intentionally trying to stay on the train like the Apex were, it just took that long to work through his issues. Moreover, One himself stated that the passengers will either solve their problems or die trying on the train. Simon wasn't the first and the rest of them almost certainly died haunted by their demons.
• The Cat will not be happy to learn that she played a role in Simon's death. She couldn't help him when he needed her most and instead turned him into something horrible. Better yet, what happens if the denizens learn that Simon's sociopathic ways was her fault?
  • The Cat is at fault for never telling Simon about the numbers when they first met. If she did, the Apex probably would never have become a menace on the Train because Simon would've pointed out Grace's lie immediately. Wait to go, Samantha.
• Hazel's case in Book 3 is a cause for alarm. Not only does she have a high number for a girl her age — 337 — but the fact that Grace and Simon are putting on the charm and trying to make her distrustful of Tuba is frightening, particularly how the two want to murder Tuba.
  • Even worse, Simon goes ahead and murders the gorilla and then we learn that Hazel is a turtle humanoid. What's going to happen if he finds out Hazel's also a Null? Would he try to wheel her too?!
  • Considering how betrayed Simon felt after learning Grace kept Hazel's identity a secret from him and the Death Glare he gives Hazel the next morning... yeah, Hazel really dodged a bullet by going with Amelia.
• We learn in Episode 8 that One-One and Amelia are locating all the cars she created during her reign, including the Unfinished Turtle car, for the purpose of quarantining them. And the first episode of the season shows that the procedure doesn't take into account if either passengers or visitors from other cars (like the Corgis from the Corgi Car) are present. How many would be isolated and sent flying by the moving car, maybe even suffering worse injuries than a bruised rib like Simon.
  • Hazel just being inside a car when it's scanned will get it quarantined too, which means that Hazel's presence is indirectly responsible for making Tuba vulnerable enough for Simon to kill her. If Hazel ever realizes this...
• Grace's flashback in "The Origami Car" shows the train appearing indoors to grab her. This means the train can take anyone from virtually anywhere if they're left unattended for any longer than a minute.
• Do Ghoms always explode when they successfully Life Drain someone, or was that a consequence of a Phlebotinum Overdose from how ridiculously high Simon's number was? If that's the case, are they attracted to the numbers of passengers, and consider higher numbers better? If that's the case, the Hazel is in grave danger traveling with Amelia...
  • There might be some hope in that Amelia is trying to decrease her number while Simon showed no remorse at changing at all.
  • This would explain why Amelia was given that belt as it seems to shield her from any and all threats the train can pose even if she's not actively trying to defend herself. If Ghoms really do seek out those with high numbers, it would be understandable that One-One would give Amelia some kind of defense since no other being on the trains seem to pose a threat to passengers.
• If and when Lucy (the girl with the eyepatch) gets home, her parents/loved ones are not gonna like what happened... There's also the trauma of the knowledge that she killed and seeing the two people she looked at as parental figures, have a big fight, with one of them literally dying right in front of her eye...
  • What kind of pre-train life did Lucy have for her to pick staying with the two teens incompetent enough to give a girl below 10 weapons in the first place?
• Even if the Apex and Grace leave the Train, they still will be haunted that at the very least they have committed mass murder for how many years and no one they know in the real world is going to believe it in the slightest (or worse, they probably have met with numerous passengers prior who would not be grateful to see them again...)
  • Worse yet, did any of their parents get on the Train during their absence? What would've happened if the Apex and their parents met face to face? The parents would be horrified to learn that not only had their children been pulled onto this train but they devolved into a bunch of serial killers.
  • Moreover, how many Apex members are so indoctrinated that they will continue to refuse the idea of change because of Grace's lies? Or worse, will those members make their own New Apex cult to continue everything Grace started?
• If Grace ever returns home and learns the tale of Tulip Olsen, what kind of horror will come upon Tulip if she learns that this sociopathic teen nearly killed her reflection? Better yet, what happens if Grace ever learns of Jesse and Lake's return home?
• If there is any empathy for the Monroe parents, is that they will eventually learn what happened to their daughter. The kids will most likely be freed before Grace and will probably bring up how Grace Monroe turned them into savages. How would they react, knowing that their neglect is the reason Grace vanished and became a cult leader? Would they still be alive by the time Grace returns? Would they be on the train themselves from their problems? Did they even learn anything from this at all?
• Sure Grace decides to reform the Apex, but how many cars and denizens will not forgive them so easily? What if they decide to wheel these atoning kids as an act of vengeance? After all, this is an Infinity Train...
• It's a really good thing Hazel didn't learn what the Apex was about or met them. She would never have been able to survive as a human form and seeing all of the destruction the Apex strewn about, making her realize that Grace was a liar and wanted to turn her into a monster. Then there's the possibility of the Apex deciding to wheel her at any given moment if she turned into her turtle form, not to mention the ramifications of Grace lying to them about being a Null supporter.
• Even if the Cat didn't run away from Simon, she couldn't have stopped the Ghom. The tragedy is that either way, the Cat was unable to do anything to save him. If she came back to him to apologize, it might have softened the blow, but now the Cat must live the rest of her days with the fact that she is the reason Simon was a traumatized and broken boy whose family will never find out the truth.
• How many denizens did Grace encounter that could've told her the truth about the Train? Grace had to have been there for a long time to get a three digit number, so if she just asked the right denizen, they could've pointed her to the right direction and she wouldn't have made her bluff.
• What would've happened to the Apex kids if Grace did die, either when Simon forced them to do so or when Simon pushed her into the wheels? They'd be living with this guilt for the rest of their lives and they're so afraid to stand up against Simon that they'll be forced to hurt others and serve him to avoid given a taste of their own medicine or perhaps become hardened just like him and ruin even more lives? And what would happen to Grace's parents if they saw her mangled up corpse?
• King Aloysius isn't seen during the Apex raid of the Unfinished Car. Did he die offscreen? Did he die of old age? Did he die when his car got flung all the way to the caboose. Amelia doesn't even mention him to Grace and Simon either...

Book 4

• This Tumblr post points out that if not for Amelia influencing One to give all the passengers their stuff back (as well as let any new passengers keep theirs), then among other things, Tulip wouldn't have been able to get Lake out of the Mirror World because she wouldn't have had the Swiss army knife and its mirror, which means that Lake would have been killed by the Flecs.
  • But on the other hand, given the types of people that could potentially make it on the train, what's to say this safety feature was a good thing? What if a passenger carried something potentially lethal like a gun or knife?
• The Docent:
  • It is made of numerous hands that still have numbers on them, showing it claimed many unfortunate passengers.
  • At least one of the hands has numbers wrapping up it's arm. As the series is set before Amelia went off the deep end, this means that whoever this was, they predated Amelia and Simon's atrocities. This means that Amelia and Simon are not the first to catastrophically screw up, and very likely not the last either.
• Cow Creamer says in "The Pig Baby Car" that when Pig Baby dies, his former chef becomes "the new Pig Baby". That doesn't sound like a very pleasant process. It also brings up the rather unsettling possibility that the current Pig Baby was a passenger who was less lucky than Ryan and Min-Gi and ended up trapped in a massive, mutant pig-body for the rest of his life.
• The only good thing Amelia did was let passengers carry things on them. How many people died or given up on ever going home because she was too obsessed with her goals with being with Alrich? If she had all that time to create cars and search for orbs, she could've also given instruction guides on how to survive. Did she even realize the reprecussions of usurping One?

Fridge Logic

• The fact that symbols other than numbers (which, terrifyingly enough, includes Pi?) can be given by the train, seems to imply that the whole Number system was originally used for something else. Or it was just really broken by a Logic Bomb.

Fridge Humor

• The Engine has a surprisingly quiet Stealth Pun: After Ghom! Atticus is shot by Tulip, he lays where he lands after the Steward smacks him out of mid-air until it's in a good position for him to decapitate it. In other words, Atticus was lying doggo.

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