As Walter Clark Jr. is interviewed about his career, he reflects on his journey from homicide detective to the NYPD's youngest police commissioner.

To avoid being arrested, a petty thief leads Clark to a murdered, drug addicted young woman with a missing daughter. Meanwhile, Clark and Arroyo continue to butt heads.

Clark investigates an incident in the projects that left a gangbanger dead and a teenager injured. Meanwhile, Arroyo threatens to go public with the wire tape exposing Clark giving a criminal informant confiscated money.

When a police officer who worked with Owen and Arroyo is killed while moonlighting for a rap mogul, Clark is called to investigate. Meanwhile, Clark threatens to expose Arroyo and McKenzie's relationship.

Owen takes the lead on a murder investigation involving the brother of his former criminal informant who was killed a few years before. Meanwhile, Clark struggles with whether or not to let his recently sober mother back into his and Agnes' life.

Clark and Owen investigate the murder of a wealthy philanthropist who is also the daughter-in-law of a shipping mogul. Meanwhile, Clark’s mother asks for help with a loan shark who is harassing her.

McKenzie seeks justice for her family when bullets found at the scene of a subway shooting match the same gun that killed her brother several years earlier. Meanwhile, Owen has reservations about retiring in two years.

After learning that they are both up for a promotion, Arroyo and Owen try to be the first to make a key arrest.

Clark and the unit hunt for the murderer of an aspiring young model found floating in the bay. Meanwhile, Clark becomes a suspect when someone from inside the investigation leaks information about the latest case to Margot Dixon, a reporter Clark has been secretly seeing.

When the family of a star basketball player who was found murdered ignites a high-profile investigation, the case unearths Clark’s feelings about his family struggles. Meanwhile, McKenzie threatens to end her partnership with Arroyo after she finds out he lied to her.

When a high-end call girl is found dead, Clark learns that his archenemy, Deputy Mayor Holbrook, was her last client. Meanwhile, Diaco struggles with the decision to put his father in a nursing home.

When Clark is relegated to desk duty, he delves into Owen’s cold case in which the murder investigation of a construction worker was compromised by the events of 9/11. Meanwhile, Deputy Mayor Holbrook pulls a gun on Clark and Margot, Agnes drives away with her father, and Owen gets his long deserved promotion.