Didn’t know Hitchcock lifted the Toyshop ending. Must be some 50 years since I saw the film. Read the book recently though and enjoyed greatly. Totally unexpected stuff and v eccentric. And, of course, the name. Wonder whether one might find Gervase Fen as a village in Essex. Have often been on verge of writing a whodunnit just so I could name characters after places spotted on road signs in the county: the detective Hemmingford Gray; his girlfriend Saffron Walden; and the evil, murderous twins Brent and Furneux Pelham.