After the brutal slaying of his family, British Special Forces ex-agent John Steel arrives in New York with a singular purpose: find the person in the photograph.Judicious NYPD detective Samantha McCall is investigating a triple homicide when Steel shows up to help find the perpetrator and bring him to justice. What at first appears to be the work of a serial killer soon turns out to be a deeper level of darkness and deceit, with relentless mercenaries, a shadowy informant and ghosts from the past for both McCall and Steel all involved.As unexpected alliances and Steel's personal mission reveal a complex web of treachery, will he and McCall find a way to work together and solve the case?