Three years on from Holmes's fatal fall into the Reichenbach Falls, Watson wrestles with a murder case under his own steam. But who is the enigmatic stranger in the Coroner's court, listening intently to all the evidence? Holmes returns home and explains how he escaped death at Reichenbach, while Moriarty lost his life. Holmes and Watson must now bring a partner of Moriarty's to justice, by proving he is a murderer.