Tobias Eaton, also known as Four, is a fictional character from the Divergent series written by Veronica Roth. He is a member of the Dauntless faction, known for its bravery and fearlessness. Tobias is characterized by his strong sense of loyalty and protective nature, especially towards the protagonist, Tris Prior. In the series, Tobias struggles with his past and the expectations placed upon him. He is the son of Marcus Eaton, a former leader of Abnegation, and faces challenges related to his upbringing and identity. Throughout the story, Tobias evolves as he navigates the complexities of his world and relationships.