The story begins with a peculiar notice in the local newspaper of Chipping Cleghorn: “A murder is announced and will take place on Friday October 29th, at Little Paddocks at 6.30 p.m.” This advertisement, seemingly a joke or a party invitation, piques the curiosity of the villagers.

On the appointed evening, a crowd gathers at Little Paddocks, the home of the outwardly conventional Miss Letitia Blacklock, who claims to know nothing of the announcement. As the clock strikes 6:30, the lights in the drawing-room suddenly go out.

A masked man bursts in with a flashlight, demanding everyone “Stick ’em up!” Three shots ring out in the darkness …