As a psychological thriller and classic piece of New York gothic in the tradition of "Rosemary's Baby," "The Forgotten" gets off to a promising start. Julianne Moore stars as Telly Paretta, a freelance editor who lives with her husband (Anthony Edwards) in a dark, brooding Brooklyn townhouse. In mourning for her 8-year-old son, who died in a plane crash 14 months earlier, Telly is drifting around in a state of suspended animation, invoking her son's memory like a totem every day and visiting a psychiatrist (Gary Sinise) to work through her grief. But soon what looks like normal mourning takes on the characteristics of a deeper emotional disturbance as images of Telly's son, Sam, begin to disappear, first from a photo album and then on a home video. Did Sam ever really exist? Or is Telly the victim of a particularly cruel gaslight scheme?

By the time she and a neighbor (Dominic West) are being pursued by federal agents, a mysterious stranger and a well-intentioned police detective (Alfre Woodard), the answer becomes clear. But the more details of Sam's disappearance are revealed, the more improbable and finally preposterous they become.

"The Forgotten," which has been directed by Joseph Ruben from a script by Gerald Di Pego, features a stylish look and solid performances from Sinise, West and Moore (who seems to have mastered the art of playing women on the constant verge of tears). But what began as a relatively sophisticated psychological thriller firmly grounded in reality becomes a science fiction creature feature. This radical shift in tone results in an uneasy mix between "Eternal Sunshine of the Spotless Mind" and the "The X-Files," and one not nearly as smart as either.

The Forgotten (96 minutes, at area theaters) is rated PG-13 for mature themes, some violence and brief profanity.

Julianne Moore plays a mother in turmoil after losing her young son.