Mercy is a medical drama which aired on NBC from September 23, 2009 to May 12, 2010. The series initially aired on Wednesday nights at 8/7c, as part of the 2009 fall season, but was pushed back to 9/8c in April. On October 23, 2009, Mercy was picked up for a full twenty-two-episode first season. On May 14, 2010, NBC announced that Mercy had been cancelled and would not return for a second season due to low ratings.

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.

A fast-paced character-oriented story, focuses on the lives and loves of the young assistant district attorneys in New York, following their career paths as these passionate but naive ADAs are confronted with tough, emotional cases that challenge their limited experience – and force them to mature quickly or be overwhelmed.

The New York office of the FBI brings to bear all their talents, intellect and technical expertise on major cases in order to keep their city and the country safe.

In cases ripped from the headlines, police investigate serious and often deadly crimes, weighing the evidence and questioning the suspects until someone is taken into custody. The district attorney's office then builds a case to convict the perpetrator by proving the person guilty beyond a reasonable doubt. Working together, these expert teams navigate all sides of the complex criminal justice system to make New York a safer place.