A terrifying new serial killer begins stalking the streets of Boston, using his vast medical knowledge to systematically torture and kill vulnerable women, a modus operandi which has earned him the nickname 'the Surgeon'. As Jane Rizzoli, accompanied by detective Thomas Moore, works the case, she comes across trauma doctor Catherine Cordell, who almost died in the same fashion at the hands of another psychopath several years before, but killed him before he could do the deed. Rizzoli soon establishes a connection between the two cases, concluding that she may be on the trail of a deranged copycat.