Orphan Lady Margaret Cheyne returns home on her eighteenth birthday to live with her embittered maiden aunt and to take up her inheritance of the family jewels. The Cheyne jewels include a pendant featuring the Purple Emperor, a priceless jewel looted from a temple during the Indian Mutiny.

During her time at school in Paris, Lady Margaret has met and fallen in love with Sir Edgar Brenton, the son of an old flame of her aunt and a neighbour in the village of Hampton, where Cleek’s adored Ailsa Lorne has also taken up residence.

Lady Margaret’s return leads to a mysterious and sinister chain of events, which Cleek and Superintendent Maverick Narkom of Scotland Yard attempt to unravel, with, of course, the help of the irrepressible and ever-hungry Dollops, Cleek’s cockney sidekick.