First broadcast 28th March 1991.

Holmes thinks a woman's claim to have seen a man at her upstairs bedroom window is related to the theft of several apes.

Jeremy Brett ... Sherlock Holmes
Edward Hardwicke ... Dr. Watson
Charles Kay ... Professor Presbury
Adrian Lukis ... Jack Bennett
Sarah Woodward ... Edith Presbury
Anna Mazzotti ... Alice Morphy
James Tomlinson ... Macphail
Peter Guinness ... Jenkins
Steve Swinscoe ... Wilcox
Colin Jeavons ... Inspector Lestrade
Anthony Havering ... Secretary of the Zoological Society
Peter Elliott ... Great Ape
Michael Cox ... Zoo Cleaner