An American couple, Roy and Jessie, embarks on a long journey from China to Moscow on the Trans-Siberian Railway, seeking adventure and a deeper connection with each other. Despite their differences - Roy is an enthusiastic train buff and Jessie carries a more complex, mysterious past - they aim to rejuvenate their relationship through this once-in-a-lifetime experience. Their trip takes a turn when they meet another couple on the train, Carlos and Abby, who are seemingly friendly but harbor dark secrets.

As the journey progresses, Jessie becomes entangled in a web of deceit and danger, unraveling Carlos and Abby's true intentions. The vast, snowy landscape of Russia serves as the backdrop to an escalating tension among the passengers, pushing Jessie into a corner of moral and physical challenges. An unexpected encounter with a Russian narcotics detective further complicates matters, forcing Jessie to navigate through a maze of betrayal and trust. Amidst the treacherous and unpredictable environment of the Trans-Siberian Railway, Jessie must make critical decisions that define her fate and the future of her relationship with Roy.