The Memoirs of Sherlock Holmes

Holmes and Mycroft investigate the murder of a professor's assistant who died clutching a woman's pince-nez.

Mrs. Hudson asks Holmes to help her friend with a lodger who insists on nobody entering his room, and his secret past is uncovered.

Mycroft investigates when the Mazarin Stone is stolen from a museum, and Watson deals with the promise of a large inheritance if a third person with the surname of Garrideb can be found.

When Susan Cushing is sent two severed ears, Holmes connects the case with her missing sister.