Peter Cheyney 
You Can’t Keep the Change 

Slim Callaghan is called to Devonshire to investigate a burglary at Margraud Manor, where valuable jewels – heirlooms of the Vendayne family insured for £100, 000 – have disappeared. With his assistant, Windermere Nikolls, he discovers some startling facts – particularly about the lovely Esme Vendayne – and the mystery leads Callaghan to a shady London nightclub and a violent underworld.