Hastings: (about Farley's pies) Good pies, are they?
Poirot: No, horrible. But there are a great many of them.
This episode is based on Agatha Christie's short story The Dream, which is part of a collection called The Regatta Mystery and Other Stories (1939).
The story was first published in The Saturday Evening Post in October, 1937.
Christopher Gunning, who composed the music for Poirot, appears in this episode as a bandmaster.