Rizzoli & Isles Season 7 Episode 4 revolves around a quirky Postal Inspector, CJ, who believes she knows about a conspiracy in the Post Office. CJ believed that a postal employee, Jack, was stealing packages. When Jane and Vince investigate Jack's death, they find CJ, who thinks Jane thinks she's better than her because she's a detective.

The investigation leads Jane and Frankie to the realization that CJ is right about the conspiracy. CJ was unable to get a warrant to search Jack's locker so the cops do it. They find out from the autopsy that Jack was murdered and it was made to look like a suicide.

CJ is impressed with both Maura and Nina's knowledge of the Post Office. Jack had a peanut butter candy bar on him even though he was allergic to peanuts and it had a postal bar code on the wrapper. Nina is able to find that the package went to a bogus address and that at least 100 packages went there.

Vince and Nina stake out the Post Office while CJ rants about not being the one to take the bad guys down. The male manager is caught and arrested, but Maura has news for Jane: the killer was female.

Meanwhile, Maura struggles with remembering how to spell a term in her report but doesn't want to have surgery. Instead, she thinks she can stimulate her brain through novel activities.

To find out who killed the postal worker and what happens to Maura, watch Rizzoli & Isles Season 7 Episode 4 online.