We Are Family

A state senator is killed by a sniper's bullet. The senator had known about a factory where the workers were supposed to have disposable uniforms but the factory owner failed to get them. The senator knew that toxins attached to the clothing were making kids sick. The senator's sister took bribes from the company to prevent any further investigation on the environmental hazards. The senator had planned to step down and expose the factory. Her sister killed her before that happened. Meanwhile, Isles is upset that she donated her kidney to Cailin, three months ago, and has yet to be thanked for it. She and Rizzoli get caught spying on Cailin, who gives Isles an heirloom from Paddy Doyle. Now recovered from his spinal surgery, Casey returns to Rizzoli's life. However, he tells her that he is returning to Afghanistan to help in the soldiers' therapy there.