Ep 16. Hard Bargain

Danny Reagan (Donnie Wahlberg) investigates a case of two people who were shot to death, and he finds out that the last individual to own the weapon used in the crime had it stolen ten years ago. The search for the thief leads to a mole inside the gun registry, who has been altering records to sell stolen guns for a tidy profit. Elsewhere, Erin Reagan (Bridget Moynahan) is prosecuting a childhood friend's father for aiding and abetting an armed robbery. Her friend begs her to go easy on her father, but Erin is determined not to let personal feelings get in the way of justice. Meanwhile, Jamie Reagan (Will Estes) and Eddie Janko (Vanessa Ray) must go undercover at a bar to investigate a robbery ring believed to be operating there. Things get heated when the robbers return while they are still undercover. Finally, Frank Reagan (Tom Selleck) has to deal with a community leader who has backed out of a deal with the NYPD to support their Safe Streets initiative. Frank must try to win him back, but the man is resolute in his decision. This all takes place on Blue Bloods, Season 7, Episode 16: Hard Bargain.