Detective Emily Eden is a tough New York City cop forced to go undercover to solve a puzzling murder. Her search for the truth takes her into a secret world of unwritten law and unspoken power, a world where the only way out is deeper in.

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.

Robert McCall is a former agent of a secret government agency who is now running his own private crime fighting operation where he fashions himself as "The Equalizer." It is a service for victims of the system who have exhausted all possible means of seeking justice and have nowhere to go. McCall promises to even out the odds for them.