Frank and interim DA Robert McCoy are interviewed on CBS News where McCoy blindides Frank with a policy change. The DA's office will no longer prosecute petty crimes involving marijuana.. Frank is furious and lashes out at Garrett. He's even less happy when he realizes that Erin and McCoy are dating. 

McCoy letter offers up an apology to Frank. Erin defends McCoy to Frank and says he's never liked anyone she's dated. 

Danny's boss, Lt. Carver does a ride along with Danny where they come across a drive-by shooting in which a young mother is killed. Danny and the Lt. clash over their different styles of doing the job and Danny considers transferring to another precinct. 

The mother was killed by her drug dealing ex-boyfriend who ordered the hit out on her and her baby when he realized the baby wasn't his. Rudy, the babies father, later takes his own life. When no family comes forward to claim the 10-month-old baby, Lt. Carver considers adopting the child. Danny rethinks transferring. 

Jamie and Eddie find a young woman, Rose dead of an apparent suicide but when her grandmother says she thinks Rose was murdered, Jamie and Eddie investigate when the detective on the case writes it off.

Turns out that Rose was raped by her boss when she tried to quit. He then killed her and staged the suicide to cover his tracks.