As the Masonic Lodge Ladies' Night comes to a close and the guests drift away, a man is found in the car park, garroted at his steering wheel. Murder is no laughing matter, of course, but why look a gift horse in the mouth?
DI Percy Peach has always taken a special pleasure in taunting his superior, Superintendent Tucker, about the indiscretions of his fellow Masons - now he's been given a free hand to dig up any amount of dirt about the secret order. And, after all, wasn't the Superintendent there himself that night?