On board an unstoppable train the truth of the past finally unfolds, but will it be at the expense of everyone’s life on board the deadly express? FBI agent Emma Griffin is starting to get her life back on track. But as she gets used to the changes in her career and settling into her personal life, questions about her past continue to haunt her. When a mysterious letter appears from Feathered Nest asking Emma to help, suspicion arises. She’s being lured onto the train and she doesn’t know why. But she can’t ignore it. This is her fight, and she won’t back down. With Sam on the train an hour behind her, Emma begins the journey. Four hours closed in the train. A strange fellow passenger and a note appearing at her seat send her into an empty passenger car, where she finds the body of a murdered man, and a message addressed to her.