Premise: The Hound of the Baskervilles is a 1978 British comedy film spoofing "The Hound of the Baskervilles" by Sir Arthur Conan Doyle. It starred Peter Cook as Sherlock Holmes and Dudley Moore as Dr. Watson. A number of other well-known British comedy actors appeared in the film including Terry-Thomas (in his final screen appearance), Kenneth Williams and Denholm Elliott.
Hypothesis: The 1978 Hound of Baskerville's film did not have Terry-Thomas in it.