The atmospheric opening scene sets the tone for the rest of the movie: A man wakes up, shaves and gets ready for work, casually talks to his wife (who doesn't get out of bed), but there's an unexplained, slight sense of eeriness and a strong sense of sadness. We soon find out that his wife is a mannequin.
Martin has a (not so) carefully crafted life. He has a well-paying job and a nice house (which, honestly, I envied more than anything) and lies to people about his wife, who he says is perpetually sick. His humble happiness is soon invaded by an extremely annoying pesky kid from the house next door, and then her mother who's a prostitute, and finally by her pimp.
You kind of wish for the kid and the mother to be killed right away, they are both quite overwritten. They seem like 21st century characters: Hundred percent entitled, no sense of secrecy or decency or shame, never shutting up for a second, and of course, judging. As a viewer, you wish the worst for them. Yet this is not that kind of film. Martin's overwhelming quality is not his shyness, but his pacifism. He gives in to the invaders rather easily, and as they keep pushing him further, he never forces them back. But of course, everyone has a breaking point.
Still, don't assume that it's a revenge drama or anything violent. The overwhelming feeling is one of sadness, rather than tension or perversion, especially when we find out that the reason for the mannequin wife is not sexual. It's Martin's denial, his failure to let go and move on. It's a tragedy.
José Luis López Vázquez is simply wonderful. There are some actors who don't even have to act or recite lines, their faces have that unexplainable quality of telling stories, conveying emotions simply by being there (Lino Ventura, Alberto Sordi, Giancarlo Giannini, Brad Dourif, James Mason and a few more) and I'd consider him among this elite bunch. He portrays the harmless Martin perfectly. Carmen Sevilla is very attractive, but plays such a suffocating, assertive villain that you can't even appreciate her beauty.
I must add that I loved how they used a real actress instead of a mannequin in a few shots. It really helped to illustrate Martin's state of mind.
I also liked the direction, the music and the cinematography. The 70's were indeed the golden age of movies.