The road to hell may be paved with good intentions, but not necessarily with good sequels.

"Exorcist: The Beginning" is the fourth "Exorcist" movie. And, like the last two, it's not up to the shivery original by William Peter Blatty and William Friedkin.

Friedkin's 1973 film, widely regarded as one of the scariest of scary movies, suggested, with almost documentary immediacy, the reality of a demonic possession. "Exorcist: Beginning," much like John Boorman's "Exorcist II: The Heretic" and Blatty's 1990 "The Exorcist III," plays down realism and jacks up the nightmare.

It's a prequel to the 1973 movie, charting the earlier devil-busting career of Father Lankester Merrin, the old priest who wrestled with the devil in Linda Blair. And, like the other follow-ups, it's more visually opulent and technically prodigious, but not as real or as scary.

This overblown tale of Merrin's post-war career, which shows the sad-eyed priest battling Mephistophelean forces in Turkana, Kenya, in 1949, never tries for a moment of realism. Director Renny Harlin puts it into visual overdrive in the first few minutes, with a CGI-spiced scene of upside-down crucifixes and bloody corpses on a 6th Century battlefield. And Harlin continues to pour on the gruesome tricks, decor and makeup as we watch Merrin (played in 1973 by Max von Sydow, and here by Stellan Skarsgard), wrestling with his own loss of faith and the satanic antics in a Byzantine church buried in that old battlefield.

Though Merrin's Holocaust experiences (recalled in flashback scenes obviously inspired by "The Pianist" and "Schindler's List") made him temporarily leave the priesthood, here he gets the call: helping uncover a temple to Lucifer, and trying to purge the devil from young Joseph (Remy Sweeney), with the help of fellow Holocaust survivor Dr. Sarah Novack (Izabella Scorupco)and troubled Father Francis (James D'Arcy).

All hell, of course, breaks loose - on a vaster, but less convincing, scale than Friedkin and Blatty managed.

The movie goes too far on too little motivation - and the middle section, with its maggoty villains, roiling skies and native revolts, seems almost barmy. Yet "Exorcist: Beginning" does score a small victory. It's not as bad as you'd think.

This movie is no "Exorcist," but it's no "Alien vs. Predator" either. Preposterously written (by Alexi Hawley, from a story by Caleb Carr), but crisply directed (by Harlin), and stunningly shot (by Vittorio Storaro), it does deliver regular scary moments - even if most of them depend on the sort of horror-ride leaping-skeleton routine you'd think couldn't faze you.

Harlin may not make nonsense plausible, but, as he proved in "Die Harder," "Cliffhanger" and "The Deep Blue Sea," he can keep nonsense cracking along and shocks popping. "Exorcist: Beginning" is a terrific-looking film - as you'd expect from anything shot by Storaro - and sometimes even a reasonably well-acted one. Merrin is played by von Sydow's fellow Swede and Ingmar Bergman stage company alumnus Skarsgard, and it's a surprisingly good choice, as are the angelic-faced Scorupco and Sweeney. Skarsgard suggests the kind of torment, angst and horrible illumination that shape the elderly Merrin; we can imagine him aging into von Sydow.

What we can't imagine is how, in any prelude to the somewhat realistic world of the original "Exorcist," a man who went through the events shown here wouldn't wind up in an asylum - even though we can see why he'd have a grudge against the devil.