HIGHLANDER: ENDGAME —*— Christopher Lambert, Adrian Paul, Bruce Payne, Lisa Barbuschia, Donnie Yen, Adam Copeland; rated R (violence, gore, sex, nudity); Carmike 12 and Ritz 15 Theaters; Century Theatres 16; Cinemark Jordan Landing Theaters; Gateway 8 Cinemas; Loews Cineplex Holladay Center, Midvalley and Trolley Corners Cinemas; Megaplex 17 at Jordan Commons; Redwood Drive-in (with "Scary Movie").

Many are the occult mysteries that haunt the earth, but few remain as inexplicable as the success of "Highlander."

A determinedly dopey sword-and-sorcery movie released nearly 15 years ago, "Highlander" still struck a chord among fantasists and action fans — even with its unhinged decision to cast the French-accented Christopher Lambert as a Scottish swordsman and the burr-impaired Sean Connery as some sort of Iberian warrior.

Since then, however, the hokey setup has spawned two movie sequels, a TV show, a TV spin-off and endless conventions and merchandise — proving once again you really can't go broke underestimating the American public. This third and supposedly final sequel, "Highlander: Endgame," may be the ultimate test of that adage.

As incomprehensible as ever, this installment — which opened without previews — has something to do with an upcoming duel of the immortals, in which chief deathless good guy faces down chief deathless bad guy. But trying to get any more sense out of it is like trying to get a stock tip by casting the runes.

There are, once again, the usual swordfights and beloved beheadings, along with some martial-arts moves to keep younger fans happy. There are also a few lively touches, including knights on motorcycles (shades of George Romero's old "Knightriders") and monks with shotguns.

What there isn't is anything resembling a plot (a fact so apparent even to first-time director Douglas Aarniokoski that he pads the film with constant flashbacks and dream sequences). Instead of the chess it's named after, the film soon turns into a big-screen Chinese checkers, with heroes literally leaping over each other and very little harm being done.

The desperately serious Lambert, still trying to touch bottom 16 years after "Greystoke," remains ze strahngest Scot we haf ever heard; as his stalwart young friend, Adrian Paul frowns and flexes with equal determination. Casting them together is at least a good commercial idea; for diehard fans of the series, having the movie Connor MacLeod and the TV Duncan MacLeod in the same story must rank alongside the thrill of seeing William Shatner and Patrick Stewart together in "Star Trek Generations."

For the rest of us, though, it ranks somewhere alongside — well, sitting through "Star Trek Generations" again. And although Bruce Payne offers a few campy thrills as the villainous Jacob Kell (think Ian McKellen's Magneto, only more deliciously unhinged), anyone but the true believer will sit through this fantasy pondering the most mundane questions, such as:

If these guys are immortal, how come they're all going gray or bald or wrinkled?

And if they are really dedicated to helping humanity, why do they keep turning out stuff like this?

"Highlander: Endgame" is rated R for violent swordplay and martial-arts action, gore, simulated sex and male and female nudity. Running time: 88 minutes.