Some detective guy or something is hired sort of by this lady to do something or other and she has a twin sister who is identical in every way but hair color but she keeps saying things like "we are identical only physically" and she's being harassed by some mobsters that want her diamond and then there's this other guy who charms all the ladies and all of a sudden he's revealed to be a race car driver and the diamond is fake no wait it's real no wait here it is.
This is the impression I am left with after watching this movie. The Devil With Seven Faces is one of those movies where nothing really happens for 80 minutes and then there's some crazy plot twist and the movie is over.
It's not especially violent, though there are plenty of people getting shot and and scrunching their faces up while their hand shoots up to where the bullet hit them and staggering around for a few seconds before turning and falling on their backs.
It's also not particularly suspenseful. I admit I was bored with the movie and had trouble paying attention to it but it's the kind of suspense movie where basically everyone is secretly on the same side and yet want to kill each other so any suspense is ruined because it's just a bunch of secret backstabbing.
I'd like to say that the dialog was natural sounding but it really wasn't. You had the smooth guy flirting with the ladies with such classic lines as, "It's my job to save beautiful women" or whatever. Maybe back in 1971 that was pretty hot but nowadays that would just get you pepper sprayed or tasered, even if you did save the woman's life.
At one point my attention span collapsed into itself under the sheer mass of the boringness that is The Devil With Seven Faces, creating a black hole of apathy which was, speaking from a physics standpoint, impossible to get out of. Impossible I tell you! I had resigned myself to my fate, floating around in that black hole, my body reduced to it's most basic elements when I was saved by the sudden appearance of the heroine in some kind of Japanese cartoon wig?!?!?!
If there is an explanation for this in the movie I missed it. I assume it was to remain inconspicuous? You know, "Well, I know you said she'd be at the beach, but all I saw was this one woman in a giant blue wig just sitting there in the middle of everything. It seemed suspicious but the woman we're looking for is blond so obviously that wasn't her."
So I guess I really can't recommend this movie. The only good part is the wig and I took that picture up there for you so you really have no reason to watch the movie. You could just look at that picture for 90 minutes, or maybe look at the title screen first for the full effect.