|Occupation|| Creator of the Maze|
|Appearances|| The Kill Order|
The Maze Runner
The Scorch Trials
The Death Cure
|Portrayed by||Dylan O'Brien|
In "The Kill Order", Thomas gets an operation for him to get the Swipe, so he can be sent in the maze with the other Gladers. Through the operation, Teresa is by his side the whole time, scared to what'll happen to her and Thomas, but calm, believing that WICKED will find a cure for the Flare for the sake of humanity. He is then put into the Box and lifted into the Maze.
In The Maze Runner, Thomas wakes up in a lift with no memory except for his name. When the lift opens he is surrounded by other kids who also have no memory except their names. This place is called the Glade. The Glade is surrounded by a maze with stone walls. Every morning, the doors to the maze open, every night they close. The gladers do not want to be stuck in the maze when the walls close, or they could be stung by hideous monsters called Grievers. When Thomas is in the Maze, he makes a friend, whoss name is Chuck.
When Thomas discovers Runners go into the Maze to try to find a way out, Thomas feels like he should be a Runner. Then, a girl comes out of the Box, Alby and Newt call over Thomas because they feel that the girl and Thomas have a connection. Thomas denies having any memory of her, but he does feel like he knows her. The girl is in a coma and the MedJacks take care of her.
At night, Thomas sees Minho dragging Alby towards the Glade, but Thomas knows they'll never make it in time because the walls are beginning to close. Thomas rushes into the Maze to help them, but when he is in the Maze, the walls close. Minho gets angry at Thomas for not staying in the Glade, Minho is certain they will die now. He leaves Alby by the walls and runs off. Then, Thomas hears a griever, Thomas is scared but climbs the vines on the side of the wall and ties Alby up there. Thomas eventually mets up with Minho again and the grieves are chasing them. Minho tells Tom to follow him and they go to the Cliff. The grievers are still chaingg them, but Minho has an idea based on what Tom did by the vines. They both stand at the edge of the Cliff and when the grievers run at them, the jump away and the grievers fall down. In the Cliff, there is a Griever Hole, where things in the hole disappear.
Then, morning comes and Tom takes Alby off of the wall vines. Tom, Alby, and Minho are the first people to survive in the Maze for a whole night. Alby is stung by the grievers, so is is taking an antidote. When Tom visits Alby, Alby grabs himself and chokes himself. Tom calls for Newt and Newt helps Tom. They get Alby to stop and Newt says that Alby is crazy even though Alby says that he was being controlled. Also, after they make it out of the maze, Tom is elected Keeper of the Runners, he takes Minho's place. When Tom visits the girl, she speaks ih his head, he finds out her name is Teresa. Later, Tom discovers that Teresa triggered the End. no one knows what this means, but soon the walls do not close and bad things begin to happen.
When Teresa is fully recovered, she rushes to Tom. They talk and Tom feels a small feeling for her.
Grievers begin to take one kid each night.
Tom and Teresa eventually figure out a code to the Maze. Thomas gets stung purposely by Grievers so he can remember his life before the maze. He learns that there is only one escape. Through the Griever hole. The Gladers make it through the Griever hole, losing half of their number, including Alby. They are greeted by someone who works for WICKED and Gally. Gally takes a knife and throws it at Thomas, but Chuck bravely takes the hit by jumping in front of Thomas. Thomas feels guilty because he had promised Chuck to get him out of the maze safely. Then a rescue team comes in and seemingly kill the WICKED member, rescuing the gladers.
In The Scorch Trials, Thomas and the other gladers are rescued, only to find out that it was all a hoax. Teresa is taken and given to Group B, an all girl experiment that has been run exactly the same as the gladers. Phase 2 of trials begin and 'The Rat Man' (known as Janson in The Death Cure) from WICKED tells them they have two weeks to travel 100 miles of wasteland, in order to reach a safe haven and be given a cure for the disease flare. On the way they meet Brenda and Jorge, supposedly infected with flare, and make a deal to reach the safe haven together. In the end, about half of each group make it to safe haven, where they have to defeat new and even more hideous monsters before finally being transported to safety.
Thomas awakes in a white enclosed room and is stuck in there for weeks until it is revealed to him that he and his friends will be able to get their memories back. The group are then informed that some of their members, Newt included, have not developed immunity to The Flare and are ultimately dying. Newt, Minho, Frypan ,and Thomas refuse their memories and are sent back to their rooms. Frypan decides to recieve his memory, leaving the group. They then formulate a plan to escape with the help of Brenda and Jorge. They manage to escape, but are lead to believe that Teresa and the others have all escaped without them. Thomas and his possy escape to 'Denver', a city believed to be quarantined of Flare. However things turn out horribly and Newt joins his fellow Cranks (infected people), and after both Teresa's group and Thomas' have shrunk considerably, they meet up again and join forces with Gally and an resistance group called the Right Arm. In an exploding final journey, Thomas leads an evacuation of over 500 immunes from the WICKED compound just before it is blown up. He nearly dies, but Teresa throws herself in the way and is crushed under a concrete slab. Tom says that he is very sorry and she says that she is too and says that she only ever cared for, but Tom doesn't hear the rest and she dies. 200 of the Immune get out with Thomas, Brenda and Minho, they emerge in 'paradise' and it is implied that they will repopulate the earth with their immune genes and kick-start earth again. The end is when Tom kisses Brenda.