After a short time in Afghanistan, Officer Jenn Penton patrols Boston with intensity and a sense of purpose, particularly when it comes to getting drugs off the street; Greg Dankers and the Fugitive Unit search for a drug dealer.

The department's gang unit targets a well-known figure; the fugitive unit cases the streets of Charlestown for a local suspect; patrol officers traverse the city streets.

The head of the police department's drug control unit plans a raid on South Boston's biggest suspected dealers; patrol officer Jenn Penton decides to try speed dating.

A string of gang-related shootings has the police department on high alert; a 20-year-old is shot in a local barbershop; the fugitive unit tracks a robbery suspect.

Robert Twitchell is promoted to sergeant; Officer Myles Lawton deals with the approaching anniversary of his father's murder; an alleged shooter gets away.

An officer works with the SWAT team to capture a suspect; Greg Dankers works days tracking down criminals while his wife works at night; patrol officer Jenn Penton has lunch with her mother and sister.