From Gates of Heaven's pet cemetarians to Fast, Cheap & Out of Control's naked-mole-rat enthusiast to Mr. Death's ethical executioner/Holocaust denier, filmmaker Errol Morris has made a brilliant career of getting up close and personal with obsessive personalities. In his new documentary, Tabloid, Morris finds perhaps his most entrancing subject yet: Joyce McKinney, a former beauty queen whose post-pageant life has led her, inexorably and repeatedly, into tabloid scandal. These scandals span continents and decades, and they involve such crazy twists that I'm tempted to avoid all spoilers and just order interested parties to the cinema. But the notion of spoilers doesn't really apply to plot points that played out in the international media, so here's a short, relatively surprise-preserving synopsis: As a young woman, McKinney fell head over heels in love with a young man, a Mormon missionary-in-training who was soon sent overseas. In McKinney's mind, her fiancé had been kidnapped by a cult, and she promptly set about rescuing him—hiring a team of helpers for an international rescue effort that saw McKinney and company track her "kidnapped" lover to the UK, which resulted in criminal charges and vast tabloid interest in the "Mormon sex-in-chains case."

This is just the tip of the Tabloid iceberg, which cracks and fractures into an array of contradictory narratives. At the center of all of them is Joyce McKinney, now a middle-aged Southern belle who recounts the story of her one true love (and the "tabloid nightmare" of her life) like a real-life Blanche Devereaux. McKinney's flair for self-dramatization is a gold mine for Morris, who captures every loquacious coo and trill at point-blank range. (Invaluable offscreen costar: the Interrotron, Morris's patented two-camera system rigged with two-way mirrors that allows subjects to see and make eye contact with Morris while "talking to the camera"; viewers will feel like McKinney is flirting directly with them.) McKinney's honey-dripping gifts also provide the movie with an incriminating stickiness, as viewers find themselves somehow rooting for a woman who may be the very model of a modern major sociopath. Whatever the truth of her words and deeds, McKinney gives the performance of a lifetime; if documentary subjects were eligible for Oscars, she'd be up for best actress (and Arthur Agee's mother would've won best supporting actress for Hoop Dreams).

Ultimately, Morris's unfettered access to the Joyce McKinney Experience comes with a cost, as viewers are left not just with intriguing mysteries (was it love or rape? Was Joyce a part-time dominatrix? Is she nuts or not?) but also with irritatingly unanswered questions. Where, for instance, did the funds for McKinney's vast international adventures come from? You get the sense that McKinney waved away all vulgar talk of money and Morris was in no position to push her. Still, even the slipperiness of Tabloid's stories is made part of the story, as Morris outfits his film with tabloid trappings, from superimposed shock headlines to tantalizingly unreliable witnesses. It's a trashy thrill ride that doesn't require you to boot down your brain.