On holiday in Chile with her best friend Kristen, Emily is having the time of her life. Until one night, she finds their hotel suite covered in blood. Kristen claims a backpacker attacked her. She shouted, but no-one heard. She struggled, but he was too strong. She had no option but to kill him. With no evidence of the assault, Emily must help her hide the body. . . Back home, Emily tries to forget what happened, but a surprise visit from Kristen forces her to confront the events of that night. As the walls close in, Emily asks herself: can her closest friend be trusted?