Through its profile of Mercury de Sade, a computer programmer obsessed with the erotic potential of alien life, Extraterrestrial Sex Fetish introduces a new perversion into the lexicon of sexual pathologies: exophilia, an abnormal attraction for beings from worlds beyond earth.

Unlike other fetishes, whose objects may be difficult but not impossible to obtain, exophilia is a sexual desire for something that is literally not to be found on earth. The necrophile can rob a cemetery, the foot fetishist can steal shoes, but where is an alien sex fiend to find the objects of his desire? A basic inability to satisfy his fetish inspires sadism in Mercury de Sade, and though obsessed with extraterrestrials he is thus compelled to victimize a series of "ninfas" or young girls...

But can a human, however alluring, ever compensate for the fantastic sexuality to be expected of extraterrestrials? If aliens are more intelligent than man, then might they -- must they -- not be more sexually advanced than man too?