OK, so my summary line is a cheap trick. But the movie is full of them and it gets absurdly praised, so...
I caught this one on TV (uncut, as TV here shows all movies, that's for you Americans who might say I didn't like it because I saw a cut TV version - fortunately that's only an US thing), and had no idea about what it was. I switched on, caught the last minutes of a show, and the movie began. Within a minute, I was begging it was a comedy, given the particularly ridiculous clichéd beginning (yes, it's a bad movie-within-the-movie, I know, but what a way to try to keep the viewer interested! I don't even know why I didn't switch channels). And, yes, in fact the movie turned out to be a comedy, albeit an unintentional one.
Marina Zudina is pretty enough, but gosh, what a dreadful performance! While casting a foreigner in the role is smart enough (she doesn't talk so bye bye language barrier), yet, sorry, Marina baby, playing mute doesn't mean impersonating Harpo Marx. Her acting is unintentionally funny in many moments, just look at her when she draws an X in the air while stalked by the killer. He wants to kill you, it's no time to play Zorro. We get plenty of "running upstairs" stuff passing for tension, as in the worst slashers, and things like pulling a carpet and a bad guy shots the other. Ugh! Will Hollywood ever learn? Yet the best/worst pearl is having a guy electrocuted in a bathtub and... Well, I have never seen anyone being electrocuted to death in a bathtub, but I'm sure you can't see the blue cartoon rays in real life, do you? And how about immediately trusting a mean-looking guy because he SAYS he's a cop, and not asking him to show you his credentials? OK, so he turns out to be a real cop. But still, not asking for the badge makes no sense (plot-wise, we could always think the credentials might be phony or he might be a crooked cop. Screen writing 101). And how about the big twist? Don't tell me you didn't see that coming from 200 miles away...
I feel sorry for poor old Alec Guinness and his useless stock footage cameo. Now I think about this, what's the point in giving him a "Mystery Guest Star" credit... in the END titles? The movie's over, there's no mystery anymore, and everybody and their brother have identified Guinness (even non-movie buffs will recognize "the old guy from 'Star Wars'"). Yet better off this way, so we can pretend it's not the late great actor.
People keep comparing this to, of all people, Hitchcock. I suppose it has to be John Hitchcock the milkman, as the late Sir Alfred would feel embarrassed out of watching this, let alone making it. And this gets a 6.8/10???? It's Bottom 100 material! But then, we're talking a rating system that allows 'The Lord of the Rings: The Return of the King' to appear as the third best movie ever made (check Top 100), so...
2/10.