Source Code — Characters & Cast

Initially to understand what has happened to him and get home; ultimately to protect the passengers as people rather than complete an assignment.

Begins disoriented and compliant, becomes furious and investigative as he grasps how he is being used, and ends in a state of chosen purpose — trading the pursuit of his own survival for the chance to save people he has been told cannot be saved.

To encourage the man she believes is her friend Sean to take a risk with his life; to make the moments she has count.

Unchanging by design — she experiences the same eight minutes each time — yet her warmth and candor progressively reorient Colter's priorities, turning an intelligence exercise into a rescue.

Duty to the mission at first, then duty to Colter as a human being owed the truth and a choice.

Starts as a rigid voice on a monitor delivering procedure, and gradually recovers her sense of obligation to the soldier behind the data, eventually acting on it at real professional cost.

To prove and preserve his technology, and to secure the funding and authority that come with it.

Remains fixed — his conviction that the program's value outweighs any individual claim on it hardens rather than softens, making him the film's argument for utilitarian science without conscience.

A nihilistic conviction that destruction is a legitimate answer to a broken world.

Concealed among the passengers as an ordinary commuter, revealed as the film's human threat and, tellingly, the least interesting mystery in a story whose real question is what Colter owes the people around him.