Odin turns up at Sherlock and Joan's door. He's bringing an 80/20 case for them to examine, Wesley Conrad, a mystery podcast host who claims a British documentarian has plagerized one of his cases. Conrad has threatened to kill shoot up the theater while the film is being shown. A body is found during an unsolved-mysteries tour. A similiar murder was committed 15 years previously. They decide to revisit the older case to look for a connection to the new one. Sherlock offers to help Conrad. Erika Vanderway said her late husband Hampton committed the first murder. The Jane Doe was a model named Camille who had been staying at a model apartment. Sherlock finds a secret elevator to the courtyard below, where the victims were found. The building's owner, Peyton Trask, admitted to moving the body so he wouldn't have to deal with housing authorities. Camille had been trying to help her sister Regina, a heroin addict. Sherlock pretends to be a gas-company inspector to check Conrad's studio, where he finds several pistols and ammunition. Marcus and Gregson feel that the same person killed Regina and Camille. The M.E. said a private eye was looking into Regina's death for Camille, but he's also been killed. Sherlock tells Odin he has handled Conrad. He wants Odin to babysit such potential murderers, like as he did with Conrad. Odin asks if Sherlock and Joan would help if he changes his methods, and Sherlock says to call. Regina's former boyfriend wants to know what happened to their daughter. Regina died on the same day she gave birth. Dr. Angela Hardy, Regina's drug counselor, was acting as a go-between with an adoption agency. She killed both sisters and the P.I. Conrad killed his parents, then himself, with a knife. So Odin isn't changing his methods.