Adulterous lovers, Sandra and David are called to the Torrances’ flat for evening drinks. However, no one is home. What first appears to be a simple mix up of dates turns to something far more sinister when the pair are locked in and, all at once, framed for murder.
Part of the triple bill Rule of Three, which also features Afternoon at the Seaside and The Patient. And presented in the triple bill The Rule of Thumb which again features The Patient but with the addition of The Wasp's Nest (in place of Afternoon at the Seaside).