Christie’s script begins with a description of the setting: The Great Hall of Monkswell Manor. The Hall is the lounge of Mr. and Mrs. Ralston’s newly opened guest house and contains several tables and chairs, as well as doors that lead to offstage sections of the Manor.

The play begins with all the lights off and the song “Three Blind Mice” playing. As the curtain rises, the lights are still off, but the music fades. The audience hears a woman’s scream, some concerned voices, and police whistles. These sounds fade, and the audience hears a voice on the radio reporting a murder being investigated by Scotland Yard.

The lights come up, revealing Monkswell Manor as the radio continues to report on the murder of Mrs. Maureen Lyon, and then turns to the snowstorm along the Scotland coast. Mollie Ralston comes in, turns off the radio, and takes off her gloves and coat. She calls for Mrs. Barlow, but gets no reply, and heads offstage.

Giles Ralston, Mollie’s husband, enters, calling for her while taking off his coat. She reenters the stage, and they talk about their supposed errands—her to the village and him to find chicken netting (however, it is revealed at the end of the play that they were off buying each other anniversary presents).