The Beresfords first real case involves the theft of a valuable pink pearl. Among the guests staying at the Kingston-Bruce's are Mr. & Mrs. Hamilton Betts and Lady Laura Barton. While Colonel Kingston-Bruce is trying to interest Mr. Betts in investing in his company, Mrs. Betts valuable pink pearl has been stolen. Not wanting any adverse publicity, Kingston-Bruce calls in Blunt's International Detective Agency. Colonel Kingston-Bruce feels sure that the thief is daughter Beatrice's inappropriate friend Mr. Rennie, while Mr. Rennie and Beatrice suspect each other. It is also probable that Lady Laura may be a kleptomanic and have taken the pearl. Leaving Tuppence completely in the dark, Tommy rushes off the Scotland Yard with a photo and finger prints of the real thief.