Maura and Jane are together again when they investigate a parade turned deadly on the Rizzoli & Isles season premiere. "We Are Family" is the first episode of the show's fourth season.
Added:

Rizzoli & Isles Season 4 Episode 1 Quotes

Maura: It must be nice to follow in your father's footsteps.
Jane: No, then I'd be a plumber and you'd be a mob boss.

I still find it amazing they can suck out an organ through a straw.

Jane