Roberts' role is less challenging, but she is very good at conveying her conflicted character's doubts. She doesn't really believe Gibson's claims until the evidence mounts and she realizes there may be more to his stream-of-consciousness ramblings than meets the eye. Patrick Stewart, stepping from the intellectual heroics of his "Star Trek" persona to a truly nasty, deluded villain, is also smooth and convincing.

Screenwriter John Mattson's previous work, "Milk Money" and "Free Willy 2," would hardly seem to pave the way for the witty and clever "Conspiracy Theory." Of course, it's also highly derivative, drawing from Hitchcock's innocent-man-on-the-run pictures, "Taxi Driver" (right down to director Richard Donner doing a Martin Scorsese-type cameo), "Marathon Man," "A Clockwork Orange" and "The Manchurian Candidate."

And though Donner will never be accused of subtlety (he also directed Gibson in "Maverick" and the "Lethal Weapon" movies), he does a fine job here of extracting excellent performances, keeping the pace in high gear and keeping us guessing about plot twists (despite the usual lapses in logic).

The result is one wild and highly entertaining ride.

"Conspiracy Theory" is rated R for violence, torture and a few profanities.