Complete story — includes the ending
Joan has her DEA number and identity stolen, leading to the discovery of two dead bodies, those of a rheumatologist who stole her identity and the mother of one of her patients. The crooked doctor was illegally writing drug prescriptions using five stolen identities. Joan realizes the patient had been secretly poisoned by his mother all his life for the attention she got to bask in. The doctor had stumbled upon this when the mother contacted one of her stolen identities and gave an entirely different medical history for her son. The doctor informed her patient. The patient murdered his mother as revenge and the doctor because she would have guessed he was the matricide. Meanwhile, Sherlock deals with an unwanted gift from Shinwell while trying to prevent Shinwell from possibly ending up dead - he proposes he and Joan train Shinwell to be a criminal informant.
Sources and content license
Source and revision history · Adapted from Wikipedia contributors, List of Elementary episodes. HTML formatting and reference markers removed. · Content license