Transsiberian (2008) on Netflix

After a period of volunteer work with needy children in China promoted by his church, Roy and his wife Jessie decide to travel to Russia by train on the Trans Siberian Railway. Roy is a naive American with a great passion for locomotives and Jessie, an aspirant photographer, is haunted by her past image as a "bad girl". During the journey, they share their cabin with a Spaniard, Carlos, and his American girlfriend, Abby. At one station Roy get's off the train to look around other trains in the yard but is left behind; Jessie decides to wait for him at the next stop, and Carlos and Abby stay with her. While waiting for Roy, Carlos invites Jessie to travel to the countryside with him where they see a ruined church in the middle of nowhere. Carlos tries to force Jessie to have sex with him, and Jessie kills him with a plank. Jessie does not report the crime and meets with Roy on the next train. Roy introduces Grinko, a narcotic division detective, who is sharing the cabin with him. Jessie finds out that Carlos was trafficking drugs and scared, she tells many lies to them. However the experienced Grinko does not buy her story.