While getting prepped in a hospital for a kidney donation, notorious serial murderer Martin Ennis escapes from custody and resumes killing. Sherlock is brought in to consult, but he bristles when he learns that he must work alongside Kathryn Drummond, the FBI profiler who literally wrote the book on Ennis. She and Sherlock have a past, and their association ended when she published an article profiling Sherlock that predicted his forthcoming addiction. Even though Sherlock and Drummond don't get along, they both have a similar idea of what Ennis is likely to do next. The only problem is that the killer isn't cooperating, and his increasingly erratic behavior has the experts stumped. Meanwhile, Joan faces eviction from her rent-controlled apartment when she learns that the man she's been subletting to during her stay with Holmes has used the place to shoot pornographic films.
