Amy (Jessica Chastain) is a compassionate nurse and single mother who is struggling with life-threatening heart disease. She works a heavy and demanding night shift in the intensive care unit. Physical and emotional limits have been reached. But when Charlie (Eddie Redmayne), a considerate and compassionate new nurse, comes to her ward, help arrives. During the long night in the hospital, the two established a strong and loyal friendship, and for the first time in many years, Amy was full of confidence in the future of herself and her daughter. But Amy was forced to risk her life and the safety of her child to reveal the truth after a series of mysterious patient deaths triggered an investigation that identified Charlie as the prime suspect.