Six people ruined Anna Matheson's life.

Four men and two women, associated with her father's train engine company, who orchestrated an act of sabotage in 1942 that resulted in the deaths of 37 others, including her only brother, and framed her father for the crime.

It's now 1954 and Anna is ready for retribution. She has gathered the six on an overnight train from New York to Chicago and announced that she has proof of what they did, and that all six conspirators will be arrested when the train arrives in Chicago.

At 8pm, the train departs. And by 10pm, one of the six has been murdered.

But Anna isn't responsible for the killing, and there's no one else on the train... Someone else is enacting their own form of revenge, and they're making it look as though Anna is behind it.

Anna needs the conspirators alive, and the irony isn't lost on her. In order to destroy her enemies, she must save them first...