The TV episode is set in a un-named English town, whereas the radio
serial clearly identifies the town as St. Catherine's in Suffolk.
The TV version of the story also shows Merlin to be a card-sharp - able to make playing cards appear
in his hand.
The tag scene of the TV episode also has an in-joke referring to US
comedy series Rowan & Martin's Laugh-In, when Steed is heard to comment "...sock it to me"
as he switches off his TV. This American series was scheduled against The Avengers in the
States and proved to be a smash hit, leading to the cancellation of The Avengers at the end
of the Tara King run.
Some of the incidental music used during this story seems to be remarkably similar to the theme of
the ITC series, Department S.