Detective Calvin Carter of the NYPD is a cop by day, drug lord by night. After a major mistake, the FBI sends in Agent Tim Jackson of the FBI to be Carter's partner as a murder is investigated.
Carter meets up with another drug lord named Vince Carpel and his number two, Zector. Donermeyer tries to learn more about Jackson while Jackson works on new projects.
Donermeyer presses LaRain for results; with the stress of a new case and their own personal issues and biases, Jackson and Carter go at each other's throats.
Donermeyer deals with some bad press; Jackson is in charge of training a pair of new recruits, fresh out of the academy; Carter meets with Vince and Zector for some closure.
Vince's location is pinpointed and a search team is sent out; Donermeyer comes to some surprising conclusions; emotions compromise a mission that leads to the loss of one of the force.
Veronica is taken to safety as her injuries provide some complications. Jackson goes after Vince, much to Donermeyer's dismay. Mel and Kat are called into the field as Carter recuperates from the explosion and his own choices.