WHATEVER'S RISING IN ACTION-FILLED `MERCURY,' IT ISN'T PLAUSIBILITY.

Byline: Glenn Whipp Daily News Film Critic

The opening scene of ``Mercury Rising'' finds our hero, FBI agent Art Jeffries, in the middle of a sticky undercover assignment. He's holed up in a bank with members of the Citizens Court of South Dakota, a militia group that includes a redneck dad with his two impressionable teen-age sons. Jeffries is trying to buy some time and peacefully end the situation. But as we all know, given that this is a Bruce Willis movie, peaceful resolutions simply aren't feasible.

There aren't too many situations that are feasible in ``Mercury Rising,'' Willis' latest movie about an alienated lone gun who takes on the system. But the film succeeds in delivering some taut, fast-paced action, and likely will please those in need of an adrenaline rush during this rather sleepy time of the movie year.

After his little South Dakota blood bath - and the subsequent knuckle sandwich Willis' Jeffries delivers to his supervisor's dental work - Jeffries is taken off undercover assignments and relegated to menial tasks such as wire-tapping. The FBI thinks he's suffering from delusional paranoia, and suspicions only grow stronger over time.

That's because Jeffries is brought in to help find a missing 9-year-old autistic boy whose parents have been murdered. It soon becomes apparent that whoever killed the parents wanted to slay the boy, too, seeing as wherever Jeffries takes the kid, bullets seem to follow. Only none of Jeffries' superiors want to believe that anything out of the ordinary is happening.

Who would want to murder a little boy? A big, bad government official, of course. It seems the child, a savant, inadvertently has cracked a top-secret military code that the government has spent $2 billion perfecting. This does not sit well with a ruthless National Security Agency adviser (Alec Baldwin in full scenery-chewing mode), thus setting up the confrontation between the ultimate company man and the rugged individualist.

One guess as to who will win.

The film is as simplistic as it sounds regarding the connections it makes between the characters. Willis, the outsider, must form a bond with an autistic child, who knows a thing or two about pain and isolation. Director Harold Becker means to explore the kinship, but never fully develops the relationship.

Granted, it's not easy to realistically explore a bond with an autistic character (rent ``Rain Man'' in case your memory fails), but Becker and the screenplay don't provide us with any substantial scenes between the agent and the boy that don't involve pursuit or danger. So, while the action moves along briskly and effectively, we never have a passionate connection with the characters other than one that develops from our natural desire to see a child protected from danger.

Baldwin, who was wildly over-the-top five years ago in Becker's ``Malice'' (``I AM God!''), is given the chance to play a stuffed-shirt psycho again, and registers well in the few scenes he's given. Child actor Miko Hughes has all the autistic mannerisms down to a science and delivers a performance that would make Dustin Hoffman proud.

Naturally, realistic details aren't at the heart of a movie that deals in government conspiracies and el train decapitations. In fact, for a child-in-danger movie, ``Mercury Rising'' has too many scenes where Willis leaves the boy either alone or with a questionable guardian.

Not too feasible. But then, as long as the boys keep moving, you don't have to think about that, do you?

THE FACTS

The film: ``Mercury Rising'' (R; violence, language).

The stars: Bruce Willis, Alec Baldwin, Miko Hughes.

Behind the scenes: Directed by Harold Becker. Written by Lawrence Konner and Mark Rosenthal. Released by Universal Pictures.

Running time: One hour, 51 minutes.

Playing: Citywide.

Our rating: Two and One Half Stars.

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Photo

Photo: Outcast FBI agent Art Jeffries (Bruce Willis) must protect a 9-year-old autistic boy (Miko Hughes) targeted by assassins in ``Mercury Rising.''