A Los Angeles deputy district attorney finds himself on a perilous mission after witnessing a murder along with a woman. The two become the target of a mob hit, and with the killers in relentless pursuit, they must find a way to escape and survive. The unlikely pair board a train heading from Los Angeles to Vancouver, thinking it will be a perfect place to evade their pursuers and hide in plain sight among the passengers. The enclosed and moving environment of the train presents a unique set of challenges and opportunities for both the pursuers and the pursued, setting the stage for a tense game of cat and mouse.

As the journey progresses, the dynamics aboard the train become increasingly complex. The deputy district attorney must protect his witness while also trying to keep their presence on the train a secret. However, the assassins are cunning and resourceful, employing various strategies to identify and eliminate their targets. The situation escalates as the train speeds through the picturesque but isolated terrain, adding to the tension and urgency of their plight. With limited options and nowhere to turn, the pair must rely on their wits and each other if they hope to outsmart their adversaries and reach their destination safely.