Stories from the set

Mia McKenna-Bruce (who played Aileen Brent) broke her leg during filming. Her stunt double was the actress's sister, Ellis McKenna-Bruce.

The main character lives in a country house called "Chimneys." It is believed to be based on a real mansion in Greater Manchester (a ceremonial and metropolitan county in England). After the end of World War II, the mansion became the property of one of the writer's relatives, and she herself often stayed there. According to Agatha Christie's biographers (she is credited as screenwriter), she often described this very mansion in her novels (though under different names).