» divergent characters · Tobias 'Four' Eaton

Tobias "Four" Eaton is a member of Dauntless and serves as the instructor to the initiates born outside of Dauntless. He was born in the Abnegation sector to Marcus and Evelyn Johnson-Eaton. His mother abandoned him at young age and he grew up with his father, who was abusive to him. During his Choosing Ceremony, he chooses Dauntless as his faction to escape Marcus. He has dark blue eyes and dark brown hair with a scar on his chin and a few freckles on his nose. He has tattooed the symbol of each faction on his spine, starting from Dauntless at the top, then Abnegation, Amity, Candor and Erudite. He gets the nickname "Four" from his instructor Amar due to having only four fears: heights, shooting someone, claustrophobia and his father Marcus Eaton.

In The Transfer, he first appears as a sixteen-year-old before his Choosing Ceremony and later as a Dauntless initiate.

In Divergent, he is eighteen years old. He is the instructor for the transfer initiates and develops feelings for Tris. He leaves the room when during the training Tris gets beaten by Peter and later says it is "not something I wanted to see," suggesting his feelings for Tris and not wanting to see her hurt. During the knife throwing training, when Tris took Al's place to stand in front of a target, he nicks her ear to show Eric that he does not care about her as if Eric finds out about his feelings toward Tris, it will lead Eric to hurt her. This is because he is jealous of Four since their previous leader Max wanted Four to take his place as a Dauntless leader instead of Eric. In Free Four: Tobias Tells the Divergent Knife-Throwing Scene, the retelling of chapter thirteen of Divergent from Four's perspective, it is revealed that he was going to leave Dauntless and become factionless but after meeting Tris, who like him came from Abnegation, decided to stay for her. During simulation initiation, he finds out that Tris is Divergent like him; he tells her to be careful about it and deletes the footage of the incident. He also finds out that Erudite are planning to use Dauntless to attack on Abnegation. The serum through which Erudite control Dauntless does not work on Tris and Four as they both are Divergent. They try to escape but caught out and brought in front of Jeanine Matthews, the leader of Erudite. She injects Four with the serum which works on Divergent and sends him to oversee the attack in control room. When Tris comes back and tries to stop him, he attacks her under the influence of serum but she does not want to hurt him at all which cause him to break his simulation and he along with Tris stop the Erudite simulation and free other Dauntless. Later he, Tris, Caleb, Peter and Four's father Marcus board the train to Amity to find the Abnegation survivors.

In Insurgent, Dauntless and Erudite traitors recognize him at Amity headquarters. During the fight he, Tris, Caleb and Susan manage to escape through boarding a train, which is full of factionless including former Dauntless Edward, who leads them to the factionless leader who is also Four's mother Evelyn. She wants Four to convince other Dauntless to join the factionless. He and Tris head towards Candor. When they reach Candor, they are subjected to truth serum, during which Four reveals that he joined Dauntless to escape his abusive father. He also finds out that Tris shot Will while he was under the influence of the serum, which makes him angry because she did not reveal that information to him. Eric, along with other Dauntless traitors, attacks Candor but gets caught. Four, along with others, secretly observes a meeting between Candor representative Jack and Erudite representative Max, who wants Eric back but the meeting becomes unsuccessful as Max gets killed. During the secret meeting of Dauntless, Four, Tori and Harrison are selected as new leaders. They sentence Eric to death and Four executes him. He also makes an agreement with the factionless to destroy Erudite and establish a new government. Later they find out about a simulation that will kill Dauntless members until a Divergent is given to Erudite. As a result Tris decides to sacrifice herself but he begs her not to. She agrees, but leaves for Erudite as he sleeps. He also surrenders himself to Erudite and later he and Tris escape the Erudite headquarters with the help of Peter. They arrive at Abnegation sector to meet the Dauntless and the factionless. He and Tris also admit their love to each other. He was deeply shocked and hurt, when he finds out that Tris aligned with his father Marcus but they later reconcile.

In Allegiant, he grieves badly because Tris was killed by David with a gun. He tries to drink memory serum but is interrupted by Christina. Two years after Tris's death, he over comes his fear of heights and rides the zip-line knowing Tris would want him to.

Tobias 'Four' Eaton is portrayed by Theo James.