Charles Cullen, a nurse who worked at multiple hospitals in New Jersey from the late 1980s to 2003, was one of the most prolific serial killers in recorded history; the story of his apprehension is vividly realised in Tobias Lindholm’s unremittingly tense psychological thriller. Jessica Chastain (a recent Oscar-winner for The Eyes of Tammy Faye) plays Amy, a nurse struggling with the demands of single-parenthood and a worsening, undisclosed heart condition. She forms an immediate bond with Charles (Eddie Redmayne), a soft-spoken new nurse whose sweet and supportive attitude fills an emotional gap in Amy’s life, helping her endure the demands of arduous night shifts. As patients begin to die mysteriously, and rumours about Charles’s past at other hospitals comes to light, Amy becomes a last hope for local homicide detectives who see a suspicious pattern to these deaths.