When two elderly bachelors were poisoned with cyanide, a strange woman was on the scene each time—and now she too has disappeared, leaving no trace. Tracking her down in a town of twenty eight thousand people is a job to tax even Inspector Bonaparte. He will need the unorthodox skills of burglar Jimmy the Screwsman and a lightning-sketch artist, as well as all the deductive and tracking skills at his command, as he trails a killer no-one has seen...