OH DEAR. NO REAL SPOILERS TO SPEAK OF.
Creak! Creak! Not the sound of unoiled hinges that you'd expect from an Old Dark House movie, but the sound of an ancient old theatrical warhorse unwisely converted into an all-star, thoroughly English country house mystery thriller. Maybe this was done to try and fit in with the Brabourne/Goodwin Agatha Christie adaptations (Evil Under The Sun, Death On The Nile etc) that were in vogue between 1974 and 1982 - this film was made in 1977 - and it has a frankly terrific cast of suspects and villains. But it's a duffer through and through.
The Cat And The Canary has, according to the IMDb, been filmed five times - the most famous probably being the Bob Hope version in 1939 - and what's most stunning about this most recent version is how they've managed to make it so completely ineffective and uninteresting when it's crammed to bursting with talent. The story's basically the same: grasping relatives gather for the reading of a will in the hope of a massive inheritance - but the lucky beneficiary has to survive the night, there's a homicidal maniac on the loose, everyone's got something to hide, and who knows about the secret passageways? There's also an entirely redundant subplot about a missing necklace which is solved fairly quickly and then dropped.
It's not scary, it's not funny and it doesn't make any sense (Edward Fox makes his entrance by smashing through a window and then tells everyone to lock all the doors and windows, presumably not counting the one he's just destroyed - and the continuity doesn't add up either, as we see the unbroken window from the outside afterwards). But there's some enjoyable hamming from Daniel Massey and Edward Fox, there's Olivia Hussey, Honor Blackman, Carol Lynley and Wilfrid Hyde-White and Wendy Hiller. Yet even with all that acting talent on view the film just never comes to life. Bizarrely, the film is directed by Radley Metzger and it's the one item on his filmography that isn't pornography. Maybe that has something to do with it?