Sitting through the thriller “The Forgotten,” it’s hard for a critic not to compose the pithy quote: “‘The Forgotten’ is forgettable!” It’s always a plus when movies write their own reviews.

But the truth is, while “The Forgotten” is little more than an extended episode of the “X-Files,” it’s an excellent episode deserving of an Emmy. Cast in the mold of high-end spooky movies like “The Sixth Sense” and “The Ring,” “The Forgotten” is a scary story designed to creep out parents. It asks the question: If your child died, would it be possible for you to forget the little twerp ever existed?

The death of a child is a terrible, terrible thing, but in the movies, I prefer my children to be puking demons, spectral apparitions standing amidst a tidal wave of blood, or simply murderous, toe-headed trolls. “The Forgotten” at first reminded me of the recent, goosebump-inspiring wannabe “Godsend” – an epic stinker that I hope still haunts Robert DeNiro. Like “Godsend,” “The Forgotten” tries to tap into parental fears about their children. But it keeps the attention of nonbreeders with a couple of sincere performances, a twisty plot that keeps you guessing, and at least three – yes, three – jolts that’ll make you jump in your chair.

Crimson-haired show-boater Julianne Moore, who adds a touch of acting integrity to whatever low rent Hollywood shlock she’s in, stars as a mother whose 9-year-old son died in a plane crash 14 months earlier. For a long time, she can’t get over it; slowly, however, evidence of her son’s existence – photos, videotapes, belongings – begins to disappear. Finally she’s told by her husband (played by Anthony Edwards of “ER” ) and therapist (Gary Sinise) that in fact she never had a son.

Ms. Moore’s struggle with madness – she is being told that she suffered a miscarriage, and her post-traumatic shock induced a set of false memories – is credible and almost touching. Ms. Moore’s character won’t let go, and the best scenes in the movie are when you doubt her, and want to believe her anyway.

She seeks out another parent (played excellently by Dominic West), who lost a daughter but has forgotten. This father and Ms. Moore’s character become partners in their search for answers. Eventually they are pursued by the evil National Security Agency (the stock villain du jour) and aided by a sassy New York cop (Alfrie Woodward) who believes that two people can’t share the same delusion.

There’s no need to spoil the plot, as the movie needs all the surprises it has. The filmmakers tread a tight rope, trying to balance a story that’s part human drama, part white-knuckle roller coaster, and part ridiculous science-fiction contrivance. Some films would emphasize one or the other, either rolling out gratuitous special effects or (my favorite editing room technique) show doors opening set to screeching orchestrations. But “The Forgotten” performs its acrobatics admirably.

While hardly a film for the ages, it’s also not one you’ll forget as soon as you’ve exited the megaplex. Maybe on the drive home.