Holmes is called in to investigate a murder. Lady Brackenstall says she saw a gang of men kill her bullying husband, Sir Eustace, but on Holmes's arrival the case seems to have been solved. Holmes is uneasy and returns to the scene of the crime, where he finds things are not as they appear to be. And Watson is curious to hear about the lady's love affair with a sea captain during a long voyage.

The Duke of Holdernesse needs Holmes's help when his son, Lord Arthur Saltire, is kidnapped from the Priory School. Holmes finds the connection between an old mystery and a teacher who has also gone missing.

Watson, on holiday in the Lake District, meets the enigmatic Lady Frances Carfax, who is being haunted by the ghost of a horseman. Holmes decides to come up to join Watson, but by the time he arrives Lady Frances has vanished without trace. Holmes investigates and becomes very curious about the ghost.