Which is too bad, because Gibson's character in Conspiracy Theory is his most interesting to date. Jerry is a New York cabdriver who self-publishes a newsletter that purports to blow the lid off all the secret dealings of the American government. Jerry is jittery and paranoid, but part of him is aware that his behavior is bizarre. When the object of his affection (Julia Roberts, as a skeptical prosecutor) visits his apartment and sees the stacks of old newspapers and the multiple copies of The Catcher in the Rye, Jerry erupts into desperate, shameful tears.

But Gibson can't resist cute-ing up his performance. He milks the character for pathos when pathos is required, but he's more comfortable running off at the mouth and spouting jokey references to Oliver Stone. The film follows Gibson's lead, converting his neurotic ramblings into harmless running gags.

The juicy premise of Conspiracy Theory is that one of Jerry's crackpot theories is true; even though his life is in danger, the filmmakers quickly undercut the sense of danger by playing up the goof appeal of Jerry's opinions. Gibson's partners in crime here are director Richard Donner and screenwriter Brian Helgeland. Donner is a clumsy action director, big on close-ups and rapid editing that obscure what's actually happening. In Air Force One, Wolfgang Peterson masterfully controlled the logistics of action on a large aircraft. In Conspiracy Theory, Richard Donner can't navigate a chase through a hallway without losing track of where his hero is.

As for Helgeland, his script is actually pretty good...at first. He provides a tricky protagonist, one too crazed for full audience empathy. He then follows this character for a good 20 minutes as Jerry drives his cab, shares his cracked worldview, has a hallucinatory freak-out, and returns to his rat's-nest apartment. To this cramped milieu, Helgeland adds a star-crossed romance between Jerry and the attorney, and he also works in a startling third-act plot twist involving the legendary CIA mind-control experiments. This twist effectively explains the weirdness of the first part of the movie, and it sets up the intriguing possibility that our hero may in fact be a villain.

The problems come in the last half-hour, where Helgeland and Donner sell out their hard-edged Parallax View-esque psychodrama and turn it into...well, Lethal Weapon. All the edginess disappears into a procession of dull shoot-outs and chases, leading to an improbable last-second love story and a ridiculous tacked-on ending.