Thomas Sanders decides to take some time to figure himself out, and introduces three different parts of his personality: Logic, Morality and Creativity (also known as "Princey").

Thanksgiving is approaching and Thomas' dad, his real dad, has asked him to help cook the turkey. But Thomas still doesn't know how to cook, so Morality pops up and reminds him that he should improve on the process of becoming an adult, which he consistently calls "adultery", to Thomas' dismay.

Thomas is feeling quite relaxed, when suddenly Anxiety pops in and ruins his peace. He calls for help on Creativity, who suggests Thomas to retire to a corner of his mind for reinforcements. He does so, and Thomas and Anxiety pop up on Lilly Singh's apartment, where she gives Thomas a few tips to, if not destroying Anxiety completely, at least bring him down enough.

New year has arrived, and as suggested by Logic, Thomas starts thinking on New Year's resolutions. Creativity and Morality also pop up to give suggestions and in the turmoil of emotions, Anxiety pops up to remind him that it is pointless to waste time on New Year's resolutions because he's going to give up fulfilling them in a month or probably less.

Thomas has decided to talk about the messages given by Disney movies, so Princey, as a Disney fan, cannot help popping up. So does Anxiety as he too is a Disney fan, because he sees the sinister undertone messages that Disney movies also provide. So Princey and Anxiety start a debate about what positive or creepy messages can be inferred from each Disney movie.

Thomas has fulfilled one of the dreams of his life, appearing on a Disney show. So the Sanders Sides appear to ask him how the experience was.

Thomas decides to have a talk with Logic and Morality. They both collide so much that they make him feel confused in his daily life, and he gives them a few examples of situations when this has happened.

Valentine's Day is coming, and Thomas is single and without hope of getting a romantic date on time. His Sides give him advice about how to approach romantic relationships, using a projection of Thomas' friend Valerie as an example of romantic crush.

Thomas has nothing to talk about. He's been procrastinating so much he didn't get anything on time, so Logic decides to discover in a Sherlock outfit, who among the Sanders Sides is the culprit for Thomas' procrastination.

Thomas asks his followers on Twitter to send him questions that the Sanders Sides will answer as best as they can.

Thomas decides to show a series of drawings about his life, when Anxiety pops up and tells him that's boring because it is a "Draw My Life" and is something that lacks originality. So Creativity pops up and sets "Daydream Mode", where he'll be in full control to brainstorm and try to get to a really completely original idea. But all the ideas they get are versions of things that have already been done.

Thomas has just had an audition where he forgot the lyrics of the song he had to sing. Tortured by this blooper, and since Roman is too bruised for what happened and Dad is taking care of him, he calls on Logic for help while Anxiety keeps torturing him on the failure he has incurred into. Logan soon realizes that Anxiety is putting into Thomas' mind a number of cognitive distortions that are making Thomas see things worse than how they probably really are. So, Logan decides to set up a formal debate between him and Anxiety with Thomas as moderator to help Thomas identify these cognitive distortions and put them into perspective.

It's been Thomas' birthday and he is wondering if he's doing what people of his age are or should be doing. Logan and Roman point out that Dad is acting as a slowdown on Thomas' adulthood and he should change his habits, forget everything that Dad provides him and act as a real adult. But the full abandonment of the simple pleasures of life provided by Dad only make him feel unhappy and depressed, so they realize something's wrong with their suggestions.

Thomas has just started using a new Mind Palace to have his conversations with the Sanders Sides, but for some reason he feels distressed about all the changes that he's going through lately and quickly pops back to his previous location, his apartment. There, Anxiety points out that the reason he's feeling that way is because he's too much time away from his friends and that he needs them in order to be consistent. Roman suggests that they could shape shift into Thomas' friends forms so that he could have them with him all the time no matter where he went, and Thomas changes all of them into their friends forms. Anxiety is the only one that doesn't want to be changed, but yet he is constantly being changed by the other Sides into four of Thomas' friends, Valerie, Joan, Terrence and Talyn.

Thomas talks about how he loves cartoons, and how he would love to be a cartoon. So, he decides to fly to L.A., meet Butch Hartman and ask him to turn him into a cartoon. He reluctantly does and for a minute Thomas and the Sanders Sides become characters of a day in the life of cartoon Thomas.

Thomas is acting strangely, like an aloof moron without common sense at all. He doesn't take care of his hair or his clothes, he has no filter on what he's ready to say about his private stuff, he loses attention of what the others tell him, and even he has lost his fear of death and survival instinct and reflexes. Logan notices this and calls Roman and Patton for help. Soon they all realize that he has no anxiety at all, and when they call him, Anxiety doesn't show up. So they decide to sink down, all of them, Thomas included, into Anxiety's room, the corner of Thomas' mind where Anxiety resides, to find out what happened to him.

Thomas and the Sanders Sides appear on Anxiety's room, which looks just like Thomas' apartment decorated as in a Tim Burton movie, with a clock that moves quickly backwards, spider webs everywhere, posters of "A Nightmare before Christmas" and a curtain with drawn spiders, something that scares Patton to death. At first they don't see him, but soon Anxiety pops up startling them all, a moment when Thomas goes back to normal. Anxiety tells them he has decided to quit, as he didn't thought he was wanted, and even though he only intended to protect Thomas, he has understood that he overdoes it and thinks Thomas will be better without him. Thomas and the others try to convince him to come back, as anxiety, even if unpleasant, is necessary for Thomas' life. But soon something strange starts happening to the Sanders Sides, as they start developing the same eye-shadow and progressively become more and more anxious the more time they spend on Anxiety's room.

Thomas has just dyed his hair purple, and the Sanders Sides, who as a result have also developed purple hair, show their opinion about the change. Patton and Roman love it, while Logan hates it and Virgil doesn't know what to say, as he doesn't want to spill too much anxiety on Thomas, since he wants to fit in the group, although he doesn't know how. When Patton has the idea that the purple hair reminds him of Nymphadora Tonks, from "Harry Potter", Thomas has the idea of using the Hogwarts Houses to sort all of the Sanders Sides into different houses based on their personality traits. As Thomas is a long time convinced Hufflepuff guy, the rest analyze themselves to see which house they would fit in, Gryffindor, Ravenclaw, Hufflepuff or Slytherin, and to try and get Virgil more integrated into the team.

Thomas is feeling really sad over the remembrance of a long lost love he hasn't been able to move on from yet. He has the idea that going to Patton's room will help him enhance the happy memories to wipe away his sadness. So all the Sanders Sides and Thomas go to Patton's room, which is full of items of Thomas' past: things he wrote as a kid, music he used to play, gadgets he had and enjoyed, photographs and drawings of his life, and more. They all get carried away with the memories, while suddenly Virgil starts feeling bad. Only Logan notices this and tells the others they must get out of the room quickly, because "habitual worriers" like Thomas, with an habitual tendency to anxiety, when they look back to the past, they tend to think that the present pails in comparison to the "wonderful memories", which in turn worsens their anxiety.

After Logan's abrupt departure, Thomas starts realizing that he cannot keep like that anymore, torturing himself with a love that cannot, and shouldn't, be back, because that wouldn't be fair, nor for him neither for his ex, because he wouldn't be happy with Thomas, just as he wasn't happy in the final times of their relationship. So, even though it's not going to be easy, and knowing that he's still gonna feel pain, maybe for a very long time, Thomas decides it's time to move forward with his life, accept that that love story is over for good, and, even if not healing completely from his pain, at least learn to live with it.

The Sanders Sides appear on Thomas because they feel in the mood for doing a video, and since it's Christmas Eve, and it's the first Christmas that Virgil spends with the rest of his new friends, Roman suggests that the four of them should wear festive Christmas "ugly sweaters" and perform a Christmas carol together. But they don't agree very much on the lyrics that Roman has written for them, especially Virgil.

Thomas has forgotten last night to go with Joan to support them to a reading for a stage play Joan had been working on. In the morning, Joan sent him a text reading "where were you last night, F Word Face", and Thomas, who thinks Joan is mad at him, doesn't know how to tell them or if he should tell them the truth at all, that he was on a date with a guy he'd just known while Joan was on their reading. Since Thomas is more inclined to lie to Joan because the truth is too horrible for him to tell them, Roman decides to transport them all to a Mind Palace shaped as a theater where he will assume Joan's form so that Thomas can practice his lying to Joan in the various situations Roman puts in front of Thomas in the form of a play, with Logan as the stage manager, Virgil as the technical operator and Patton as the director.

After a failed game and loss of motivation, Logan tries to help Thomas find the bigger picture behind everything he does in his life, while Roman tries to convince Thomas to take risks and not settle for a boring and basic life.

Crofter's has partnered with Thomas to release a new fruit-spread inspired on Logan, so naturally Logan, as a Crofter's fan is flipping out about it. Roman, however feels a little jealous as he too wants his own flavor of Crofter's.

Thomas had a conversation with a friend some days ago that made him feel iffy. When his friend asked him what he did for a living, he answered he did YouTube. His friend answered back with a question that had been done to Thomas several times before, what he "really" did for a living, like a "real" job. For some reason, this time it stuck with him. Thomas hasn't stopped feeling bad ever since, and he doesn't even know the reason why. Thinking that he should feel blessed for everything his job gives him only makes him feel even worse out of guilt. The Sides decide to help him work out this issue and discover what's wrong. They think about how Thomas used to learn and discover things in the past, and Patton has the idea that, as a child, Thomas learned new things by playing with puppets or watching puppet shows, so the Sides turn into puppets to help Thomas in this one.

Thomas and the Sides are celebrating a belated Halloween by dressing up as different monsters. Virgil, disguised as a vampire, tries to scare his friends and fails terribly. Virgil realizes that Thomas and the Sides have embraced him too much as a friend, up to the point that they don't find him scary anymore. Furthermore, Thomas has told him that Virgil being scary was only a phase of him and an "act" that is over. So Virgil decides to make a journey with them through Memory Lane to remind them of all the terrifying phases Thomas has gone through in his life, so that he can remind them that he's still Thomas' Anxiety and he still can be terrifying if he wants to.

Thomas has received the callback of his life to participate in a movie. However the callback day is the same day some of his friends are marrying. Now he's torn between lying to his friends to pursue the job of his life or losing the opportunity of a lifetime and attend his friends' wedding. Deceit shows up and puts Thomas on a trial to prove that Thomas is guilty of caring for himself more than he cares for his friends and prove to the other Sides that Thomas is not the perfect idealistic figure they think he is.

Thomas hasn't had any sleep the whole night, so he "wakes up" exhausted out of sleep deprivation. The reason he couldn't sleep is because of the anxiety he's had over the most bizarre intrusive thought about murdering his own brother which suddenly crossed through his mind while trying to sleep. It is soon that he will have to face a new Dark Side, The Duke, Roman's twin brother, who encompasses the part of Creativity Thomas constantly tries to suppress, the one that inspires on him such intrusive thoughts among other thoughts Thomas has been thinking that may be the proof that, after all, Thomas may not and may have never as angelic and pure as Patton wishes.

What to do when anxiety has a hold and you just can't let... it... leave? Obviously, Thomas deals with that quite a bit, and this evening, he turns to his number one distraction from the plagues of life: movies! The Sides are mostly on board with this... mostly. Are distractions like these helpful in anxiety-ridden situations like these?

Thomas has just returned from Lee and Mary Lee's wedding. He's resented that the bride and groom didn't seem to care about his presence any more than any other guest's, and he regrets having renounced to the callback to attend the wedding as he thinks in the end the spouses wouldn't have lost anything for his absence, while he lost something important for him. Patton and Roman try to assist him on his doubts about if it's good to be selfish sometimes or if selflessness should be the norm at all times, no matter the cost for his own mental health.

Thomas has decided to spend the day outside and go to the mall, while Roman and Virgil don't stop chastising him about his honesty wherever he goes. When he goes to a restaurant to get something to eat, he sets his eyes on a very cute guy on the next table, and Roman and Virgil start conflicting with each other and with Thomas trying to push him into saying something to that guy and at the same time avoiding it, tearing Thomas apart in the process with this conflict between his newfound feelings and his crippling social anxiety.

It’s been a difficult time for Thomas as of late, and after an especially rough night of insecurity, Thomas made a deal with Logan to get his life in order! But it’s not going to be that easy for him to shake off all the thoughts and anxieties going through his head, and Remus is pulling out all the stops, attempting to ensnare Thomas in stronger intrusive thoughts than ever. Are all of these thoughts random? Or do they all have to do with… one thing in particular?

Thomas has found himself in a new relationship… but not everyone wants to make a big deal about it… and Roman wants to know why. Looks like a quest for the Doctor… AKA Logan… to locate the trouble hidden away… somewhere in the past…