In 1942, six people destroyed Anna Matheson's family. Twelve years later, she's ready for retribution. Under false pretenses, Anna has lured those responsible for her family's downfall onto a luxury train from Philadelphia to Chicago, an overnight journey of thirteen hours. Her goal? Confront the people who've wronged her, get them to confess their crimes, and deliver them into the hands of authorities waiting at the end of the line. Justice will at last be served. But Anna's plan is quickly derailed by the murder of one of the passengers. As the train barrels through the night, it becomes clear that someone else on board is enacting their own form of revenge--and that they won't stop until everyone else is dead. With time running out before the train reaches its destination, Anna is forced to hunt the killer in their midst while protecting the people she hates the most. In order to destroy her enemies, she must first save them--even though it means putting her own life at risk.