"Without a Trace" takes an overlong look at a kidnapping.

Kate Nelligan plays a professor of English at Columbia University, a liberated mother of one. She's well-balanced, single-minded, tough and tenacious, a model of courage.

Her son is the perfectly perfect person, too, a six-year-old who's trusted to walk to and from school. One day he doesn't make it there.

When his mother comes home from lecturing on literature, he's missing. Her estranged husband (played by David Dukes) is suspected, but he soon turns up without the boy. Then begins a long wait for a ransom call that never comes.

Adorable as little Alex, Daniel Bryan Corkill is missing too long from the movie; we develop only a passing fancy for him. We're treated instead to countless closeups of mother, brow poised at controlled worry. Will she make it through? She endures things she never envisioned: appearing on talk shows, taking a lie-detector test, talking to neighborhood meetings, resorting to psychics, hiding in the bathtub to cry and hoping when everyone else has given up hope.

Stockard Channing provides a little comic relief -- she's a real character, in both senses of the phrase. As the police sergeant investigating the boy's disappearance, Judd Hirsch -- cabdriver in the TV series "Taxi" and psychiatrist in "Ordinary People" -- provides a foil to Nelligan.

Some films offer enough psychological twisting that even if you know the inevitable conclusion, you still want to watch the process that leads to it. Those twists are missing in "Without a Trace."

Interesting details are lacking. In one instance, a suspect goes to jail when, as any "Quincy" fan could see, a simple bloodtest could have cleared him.

Obviously, what sustains curiosity is the question of whether the boy is dead or alive. On this count, it's a compelling movie. But if you know the answer, you probably don't need to stay till the end. WITHOUT A TRACE -- AMC Carrollton, Loehmann's Twins, NTI Tysons, Old Town, Roth's Seven Locks, Springfield Mall, Wheaton Plaza.