Sibling on AllMovie

The only noteworthy element of this otherwise undistinguished low-budget suspense flick is the presence of director Reginald LeBorg, who helmed numerous Joe Palooka comedies and several horror projects (including the excellent Vincent Price thriller Diary of a Madman) before taking a career dive into drive-in exploitation fare. As polished as its miniscule budget permits, this lurid psychological thriller involves the plight of a distraught widow (Susan Strasberg), whose fearsome fits of uncontrollable grief land her in the questionable care of her sister (Faith Domergue)... who, fresh out of a sanitarium, is not exactly a pillar of mental stability herself. In no time, the pair skip right through the tearful reunion and go straight to psychological warfare (shades of What Ever Happened to Baby Jane?), escalating, of course, to the point of murder. Other than some silly psychedelic depictions of the psycho siblings' increasing delirium, this film lacks the kind of operatic campiness of the suspense melodramas that inspired it.