Following the success of their version of Why Didn't They Ask Evans? (1980), the same production team reunited for this Agatha Christie adaptation, including Pat Sandys, Tony Wharmby and Jack Williams. Both productions also included the actors: John Gielgud, James Warwick, and Robert Longden.
The meeting is said to take place at Wyvern Hall. At 1:18, the clock on top of the building is shown striking 3:00am and in the foreground you can see an architectural ornament of a wyvern, presumably associated with the name of the estate.