Nifty early Hammer mystery, based on a popular radio programme. James is a wealthy scion who suddenly dies, leaving his rotten family to play mind games with the psychologically fragile daughter who inherits his fortune. All this is narrated by the wonderfully sinister intonations of Valentine Dyall, in the manner of "The Shadow."
Interesting on many levels, not least of which are the familar names in the credits: Jimmy Sangster as assistant director, screenplay by John Gilling. Already the foundations were being laid for Hammer's golden years. Gilling's script foreshadows his later work--wealthy man under the influences of exotic customs, as in The Reptile and Plague of the Zombies. James is also excellent in a dual role, though given his later career, it's a little surprising to see him playing, of all things, a yoga expert!
The real star, though, is Oakley Court, in possibly its first film appearance and looking almost exactly the same as when the Transylvanians took up residence 25 years later. And the mind games portrayed here are similar to those of Mumsy, Nanny, Sonny and Girly, which was also filmed there.