: Watson eventually deduces that Nate Campbell (Gabriel Olds) was murdering his wife to hide a massive medical fraud. He had been intentionally misdiagnosing patients with cancer to provide unnecessary, expensive treatments. Abby had discovered his malpractice through independent blood testing. Subplot: Watson vs. Detective Cortes
: This is the first episode of Season 4 that does not feature Sherlock’s father, Morland Holmes. "Elementary" All My Exes Live in Essex(2015)
: The investigation initially focuses on her husband, Nate, and a colleague, Branford Fisher. It is revealed that the three were involved in a secret group marriage (polyandry). Further investigation leads to the members of Abby’s previous group marriage, who all live in Essex and held a financial grudge against her. : Watson eventually deduces that Nate Campbell (Gabriel