Sherlock and Joan investigate the murder of the general manager of a high-end Manhattan hotel whose body is found inside an industrial laundry machine. Meanwhile, since Joan's time with Sherlock is almost up, he offers her an apprenticeship.

While on suspension from the NYPD, Sherlock investigates a suspicious hit-and-run accident involving a conspiracy theorist. Meanwhile, Watson tries to broker peace between Sherlock and Gregson.