Rizzoli & Isles Season 7 Episode 12 revolves around a case from Vince's past. In 1975, his childhood sweetheart Mary lost her little sister Wendy to a murder. The case was never solved but it inspired Vince to become a police officer.

In the present, Mary's father has been murdered and it's tough for Vince, especially when it turns out the same person killed both father and daughter. Vince must reunite with Mary and attempt to interview witnesses from 30 years ago.

The case leads to the Davenports, the family that hosted the party where Wendy was killed. The Davenports' son, Robbie, is less than cooperative when the police try to reconstruct the crime.

Meanwhile, Frankie and Nina make wedding plans despite their low income, using some unorthodox methods, while Agent Davies throws Jane for a loop when he comes to town and admits that he is interested in her as more than as a potential new co-worker! And Angela and Maura struggle to accept Jane's move, while Maura may make a move of her own to aid in writing her mystery novel.

To find out what happens, watch Rizzoli & Isles Season 7 Episode 12 online.