Detective Catherine Chandler is a smart, no-nonsense homicide detective. When she was a teenager, she witnessed the murder of her mother at the hands of two gunmen and herself was saved by someone – or something. Years have passed and while investigating a murder, Catherine discovers a clue that leads her to Vincent Keller, who was reportedly killed in 2002. Catherine learns that Vincent is actually still alive and that it was he who saved her many years before. For mysterious reasons that have forced him to live outside of traditional society, Vincent has been in hiding for the past 10 years to guard his secret – when he is enraged, he becomes a terrifying beast, unable to control his super-strength and heightened senses.

Ambitious young cops try to prove themselves in their high-stakes careers, in which the smallest mistake can have deadly consequences. At the core of the close-knit group is perfectionist Andy McNally, whose father was a homicide detective before he burned out on the job. The series follows Andy and her four colleagues -- Dov Epstein, Gail Peck, Traci Nash and Chris Diaz -- as they experience the trials, triumphs and tribulations of police work, as well as its effect on their personal lives.