Two separate homicides, at different locations, with unrelated victims, have more in common than just being investigated by Boston PD detective Jane Rizzoli and medical examiner Maura Isles. In both cases, the bodies bear startling wounds yet the actual cause of death is unknown. It's a doubly challenging case for the cop and the coroner to be taking on, at a fraught time for both of them. As Jane struggles to save her mother from the crumbling marriage that threatens to bury her, Maura grapples with the imminent death of her own mother infamous serial killer Amalthea Lank.