Another case for Reginald Brett, barrister and hobby detective: David Hume-Frazer is in some trouble. He was the prime suspect in the murder case of his cousin, Alan. Though he was never convicted, suspicion clings to him, and he wishes his name to be cleared before he marries his fiancé, Helen Layton. The case is baffling: Alan was murdered with a Japanese knife on his own grounds, in front of the library windows -- in the same place, where four of his ancestors already died "in their boots"...