Based on a true story this crime thriller has a creepy edge and builds some really clever, tense and worrying scenes with Eddie Redmayne playing serial killer Charles Cullen in a very unsettling performance. Jessica Chastain plays dedicated nurse Amy, a single mother who is also managing a serious heart condition for which she needs surgery. She has to hide her condition from the hospital management for fear of losing her job and still has to work a few more months before her health insurance activates. She is therefore relieved when new nurse Charlie arrives and befriends her, helping her with her children and her condition. Then unexplained patient deaths occur. The police find they are obstructed by the hospital who fear lawsuits and loss of reputation. Eventually Amy breaches her contract by assisting the police and is shocked when she discovers Charlie is the main suspect. As well as telling this terrifying story of Cullen, who it is believed killed hundreds of patients, the film delves into the culture of the American health system that has hospitals suspecting Cullen but simply firing him and then allowing him to get nursing jobs elsewhere. Both the lead actors are excellent here and aided by Kim Dickens as the hospital administrator and Noah Emmerich as one of the detectives. Solid drama that is worth checking out.