Jack Hill, who would gain fame for his blaxploits and Spider Baby, first filmed this seedy and fitfully entertaining piece of roughie sexploitation. Despite the title, it has nothing to do with the mondo genre—Hill's original title was The Worst Crime of All. And what is the worst crime of all? No, not the Suspiria remake. It's rape! The movie even tells you this in the dialogue.
Rape is the reason why Howard Thorne's marriage is falling apart. He spends all day at the pornography office, overseeing torture photosheets and circumventing the Comstock laws in Peoria. So when he gets home and his wife is ready for randy adventures, he's all, "ZZZZZZZ". But he's always up for raping and seems to have a special affinity for nonconsensual sex.
Thorne waxes eloquent about the natural origins of rape and spends copious amounts of movie time daydreaming about rape in exotic locations, like the beach.
This is kind of an indication that Keyhole was made by a genuine talent, as Thorne's rambling mirrors the comedic rhapsodies of a pretentious pornographer earlier in the film ("Even Freud would like this movie!"). The early goings offer lots of comedy and weirdness, but the film loses it way a bit and starts stumbling midway through.
We get twin Big Endings. In one, an Eyes Wide Shut-style costumed sex bash offers all sorts of softcore thrills. I enjoyed the woman buried under mounds of food, who is then swarmed by hungry partygoers. That's transgression! But too much of these scenes are devoted to typically 60s pool shots and such. Kinda dull.
And, of course, the rapist gets his comeuppance in a reprisal of an earlier staged torture scene. I don't care who gets nominated to the Supreme Court as long as her makeup looks like that of the judge below. Also, way to go, Jack Hill, at including the clock from earlier scenes, This is worth a glance if you are a huge Hill enthusiast, as glimmers of his style are displayed, but otherwise the director's own assessment is probably accurate: "just a cheapo junk movie".