Julianne Moore (search) refuses to be pigeonholed in her acting career, and her latest film is another twist — but one that might be better "forgotten," if the critics are to be believed.

Moore — whose movies have been as varied as “Magnolia,” “The Hours” and “Laws of Attraction” — plays the heroine in a horror flick called “The Forgotten,” (search) opening this weekend.

But the film itself has fallen flat, eliciting a chorus of groans from an array of critics.

“‘The Forgotten’ is probably how a great actress like Julianne Moore hopes this film will live in audiences' minds,” FOX News’ Bill McCuddy said in this week’s “In the FOXLight.” “One review is headlined simply ‘Forget It.’ The New York Times calls it ‘preposterous.’ And the twist late in the story is goofy, according to most.”

Grieving the loss of her 8-year-old son 14 months earlier, Moore’s character, Brooklyn mother Telly Paretta, seeks psychiatric counseling.

But a horrible shock awaits her once she gets there: She’s told her “son” is really just a figment of her imagination. Kind of like “The Sixth Sense” meets “Who’s Afraid of Virginia Woolf?” Or something.

Still, Moore is able to capture the gritty emotions and complex character elements that have set her apart as a versatile, talented actress.

“The number one important thing in a psychological thriller is the psychology itself,” Moore said. “It really does have to have some kind of emotional core.”

But the problem with “The Forgotten” is that it meanders away from psychological thriller into ridiculously-corny-spoof-that-isn’t-supposed-to-be-a-spoof territory.

Not to get all political, but it goes beyond the land of the flops into (to quote the Bush-Cheney campaign and their ilk) “flip-flop” country, according to critics.

“'The Forgotten’ would have been just fine if it had stayed the course as a psychological drama. … What it turns into would have been a rejected idea for an ‘X-Files’ episode,” wrote Associated Press entertainment writer Christy Lemire (search). “It’s often laugh-out-loud funny. And that probably wasn’t the desired effect.”

Lemire wonders why a respected actress like Moore took a role in a film like this one, directed by Joseph Ruben (search) of “Sleeping With the Enemy” fame and written by Gerald Di Pego (“Angel Eyes”).

At one stage, Telly finds a sympathetic friend in her alcoholic neighbor Ash Correll, played by Dominic West, who stars in the HBO show “The Wire.” Ash lost his young daughter in the same plane crash Telly’s son died in.

But about partway through the film, Telly and Ash’s quest for the truth becomes absurd.

“Then the federal agents show up — everywhere, all the time,” wrote Lemire. “Then Telly and Ash start playing reporter, and their physical resemblance to (‘The X-Files’ characters) Scully and Mulder couldn’t have been a coincidence.

“But here’s where things start getting downright silly, with talk of abductions and clouds shaped like UFOs and a special effect involving a whooshing vacuum sound.”

Oh well. The bizarre plot twists and changes-of-genre don’t seem to have stopped Moore — a mother of two in real life — from identifying with the grieving “Forgotten” mom, from what she’s said while promoting the movie.

“The worst thing that could happen to anybody in my opinion is to lose a child,” Moore said. “I don’t think that’s difficult for any of us to relate to.”

In fact, she said, a parent-child relationship like the one that’s the film's focus has wide audience appeal.

“If you start with something as meaningful as a bond between a parent and a child, if you give the audience kind of an entry into the story that way, you really allow people to care about these people and what they’re going through,” said Moore.

That is, unless what you start with ends up being something else entirely.

“It’s hard to watch the disappointing way ‘The Forgotten’ develops without thinking … ‘That’s IT?’ Lemire wrote. “Yeah, that really is it.”

“The Forgotten,” a Columbia Pictures release, is rated PG-13 for intense thematic material, some violence and brief language. Running time is 96 minutes.

FOX News’ Catherine Donaldson-Evans, Mike Waco and The Associated Press contributed to this report.