This is a very strange Spanish film that seems to have been equally inspired by the 1970's Italian gialli thrillers AND the earlier 60's British "psycho" films like "The Psychopath" or "Twisted Nerve" where handsome (and usually very effeminate) young men are driven to serial murder by their psychosexual neurosis. I actually like both of these "genres" a lot, but they don't necessarily mix very well (although they both do owe a significant debt to Hitchcock's original "Psycho").
The disturbed protagonist here is the sexually repressed son of a gardener who likes to play with--and mutilate--dolls he steals from a doll factory where he works. The lady of the house, a contessa (Helga Line), tries unsuccessfully to seduce him. He befriends a young boy, who he seems in constant danger of molesting and/or murdering. Meanwhile, he spies on couples having sex and subsequently murders the girls, turning them into more of his "dolls". Things finally come to a head though when he falls for the pretty daughter (Inma DeSantis) of the contessa.
The direction by Miguel "Necrophagus" Madrid is pretty incompetent and the camera-work is downright awful. This does not have the visual flair of your typical Italian gialli, but it is also way too overwrought and hysterical to succeed as a more mannered British "psycho" thriller. The lead has the right look, but his performance is often hilariously unsubtle. Helga Line meanwhile is largely wasted. Perhaps, the best reason to watch this is Inma DeSantis who, along with Sandra Mazurowsky, was one of young, ill-fated "lolita" actresses of 70's Spanish exploitation (both began working in films as teenagers and both died tragically young--Mazurowsky by her own hand and DeSantis in a car accident). DeSantis is very pretty and appealing, but doesn't show up unfortunately until at least halfway through the movie when it is way too late to salvage much. This movie is uniquely strange--if that can be considered a virtue--but there's not much else you can say about it.