The most entertaining documentary in years. By its title, Tabloid sounds like his most uncustomary lightweight film to date from Errol Morris. But Morris, unlike nearly any other filmmaker of docs or fiction features, explores psychological undercurrents in the most fascinating of ways. Any fervent seeker of true stories, the ones found under the stranger than fiction files, won’t be able to help themselves from total arrest by an entirely immersive life story. Morris, as he has done in with several films, from “The Thin Blue Line” to “Mr. Death: The Rise and Fall of Fred A. Leuchter Jr.,” to “The Fog of War,” fastens his interview subject in front of his fixed camera staring into her. This time he plants Joyce McKinney, the tabloid hot topic of 1977 to recount her unprecedented pursuit for love. Substantiated is McKinney’s recorded 168 I.Q. and her crown as Ms. Wyoming beauty queen at an early age. Now 61 years old, she is eagerly talkative, articulate, colorfully exuberant in her recollections and projects tireless intelligence before the camera, before Morris the interviewer, who gives us a window into someone more enigmatic than she first appears.

Her story involves her instantaneous love for gawky 6 foot 3 inch tall Kirk Anderson, his disappearance, godfearing, her years of working to pay for a private investigator, her hiring of two bodyguards and a pilot to travel over England, cultish Mormon brainwashing, kidnap, rape of a man by a woman, bondage, full nude massage, racy two-girl nude photographs, arrest, humility on the court stand, shameless pride on the court stand, media frenzy, competitive tabloids running two divergent accounts of supposed truth, McKinney’s contention that “I would never have sex with anybody else,” mini-Boogers and the explanation of what kind of occupation a doo-doo dipper is. If this doesn’t lure your complete attention, I don’t know what else I could say to convince you.

For awhile the story of what McKinney was doing in the years between working in Los Angeles and then going on a worldwide investigation to find her lost love is left out. All we know is that she was working three jobs – it’s a chortle when we find out that all three jobs are related (I forgot previously to include mud wrestling as a compelling teaser). Intercut between McKinney’s garrulous assertion of the truth are Morris’ interviews of past acquaintances and an excommunicated Mormon from Utah who blasts his former Church with “indoctrinating” him into repression. This Mormon defector, Troy Williams – now a Salt Lake City radio host – is mostly there to explain Kirk Anderson’s background and mental impulses.

But others like Daily Express reporter Peter Tory, Daily Mirror photographer Kent Gavin and pilot Jackson Shaw recall McKinney’s wildest charades for attention and the likelihood that she wasn’t all that devout. During the course of her public scandal she sold her story to the Daily Express, talked about writing her book, went on television – at times to clear her name, at other times to boast about her beliefs in monogamist love. McKinney defends that several figures, including a later not to be found Steve Moskowitz, were out to taint her name for money and fame.

What’s amazing about Morris’ talent is the way he starts sneakily with a mind-boggling puzzle, then conducts interviews that gradually squeezes the pray tell juice out, until a broader picture is painted. And when Morris creates a broad picture – through assembly of close-up interviews, television archives, magazine collages, video home recordings – he blows it up into something wilder that turns the whole story back on its head. By the time you think the whole puzzle is laid out, it’s not, since it’s never quite one patch ending with Errol Morris – especially when an opportunity to explore genetic cloning can be had. He makes documentaries that go into further and further diversions that never can be predicted.

But with finality, the one thing that the unsinkable Ms. Joyce cannot perceive is that she hasn’t a clue as to what obsession is and that she’s hooked by it by infinity, incapable of ever looking possibly at a second object of desire. Morris explicates a woman of inconceivable immensity but leaves it to us to deconstruct her.

106 Minutes. Rated PG-13.

DOCUMENTARY / MAN MADE DISASTER / LATE NIGHT VIEWING

Film Cousins: “The Sugarland Express” (1974); “Heidi Fleiss: Hollywood Madam” (1996); “Kurt & Courtney” (1998); “Mr. Death: The Rise and Fall of Fred A. Lechter Jr.” (2000).