A dentist lies murdered at his Harley Street practice…The dentist was found with a blackened hole below his right temple. A pistol lay on thefloor near his outflung right hand. Later, one of his patients was found dead from a lethaldose of local anaesthetic. A clear case of murder and suicide. But why would a dentistcommit a crime in the middle of a busy day of appointments?A shoe buckle holds the key to the mystery. Now – in the words of the rhyme – can Poirotpick up the sticks and lay them straight?