Death at the Helm (1941) is a Golden Age detective novel featuring recurring amateur sleuth, Dr. Lancelot Priestley, where Inspector Waghorn investigates the poisoning of two people on a grounded motor cruiser, a complex "howdunnit" rich in botanical details about poisons, set against a backdrop of wartime England. The book is praised for its well-clued puzzle, detailed detection, engaging characters, and poignant ending, balancing the technical mystery with emotional depth.