The daughter of scientist Professor Presbury sees her father's face at her second-storey window; Holmes connects this with recent zoo thefts.
Quest roles:
Colin Jeavons(Inspector Lestrade), Charles Kay(Professor Presbury), Adrian Lukis(Jack Bennett), Sarah Woodward(Edith Presbury), James Tomlinson(Macphail), Peter Guinness(Wilcox), Steve Swinscoe(Jenkins)