Ann Lebrick cheerfully accepted an assignment to photograph the ocelots of Miss Estelle Marlow. On arrival at the Marlow estate, Black Tor, where she was to stay for a week, she found herself in a brooding atmosphere of great wealth, guarded isolation from the rest of mankind, and black clouds of suspicion. She became uneasy at Miss Marlow's apparent lack of interest in photographs of her ocelots. She was worried when her fiance telephoned her, imploring her to leave at once. She was literally scared when Justin Marlow, old and heartbroken, revealed to her a secret that had been kept for twenty years. Then a sensitive photographic film was developed, proving murder...