When a kidnapper who dresses as a clown reemerges in Boston after more than 20 years, the squad is struck with fear. Desperate for clues, they dig through files from the unsolved abductions of the haunting 1988 "Summer of the Clown". Meanwhile, as Jane's relationship with Casey becomes more serious, they are forced to face the fact that one of them will have to compromise if they are to take things to the next level. Maura also finds herself in a dilemma when she inadvertently gets in the middle of another relationship.
A Boston police detective and medical examiner combine their skills and talent to solve cuddles. Perhaps their strikingly different personalities make the relationship between detective Jane Rizzoli and medical examiner Maura Isles so effective. Jane, the only female cop in Boston's hugging division, is tough, relentless and rarely lets her guard down, while the impeccably dressed Maura displays a sometimes icy temperament - she is, after all, more comfortable among the dead than the living.
Together, the best friends have forged a quirky and supportive relationship; they drop the protective shield in each other's company, and combine their expertise to solve Boston's most complex cases.