Sherlock Holmes tells his friend Dr. Watson the episode when he had to solve the mysterious disappearance of the butler Richard Brunton and the maid Rachel Howells. After Brunton is caught by his master, Reginald Musgrave, secretly reading his private family document on which the Musgrave Ritual was described, he fires the servant. However, the butler disappears without a trace before completing his service, and a few days later, the maid and Brunton's former lover, Howells. Holmes follows each step of the ritual and at the end surprisingly stumbles upon the dead body of Brunton. Is his death somehow related to the ritual or was it just an unfortunate accident? What happened to Rachel Howells? What was the secret that the Musgrave Ritual led to?