The Forgotten (film)

The Forgotten is a 2004 Suspense/Thriller by Joseph Ruben. Told that her child, Sam, never existed, Telly Paretta find physical evidence of Sam's existence and tries desperately to find someone to believe her, helped by Ash Correll, another parent who had apparently lost his daughter. As she unravels the mystery she discovers greater forces at work trying to hide the fact, and that the government is in bed with aliens to cover up abductions and experiments on the human psyche.

It exhibits the following tropes:

 * Government Conspiracy: With aliens, no less.
 * Humanoid Abomination: The alien agent known only as A Friendly Man. He gets shot, has cars crash into him, and his smile never falters, even as he's yelling in people's faces and banishing them to the horizon.
 * Laser-Guided Amnesia: Every parent is made to forget that their child ever existed. The clean-up squad missed a few photos.
 * Meaningful Background Event: The passengers are blissfully unaware, but the audience sees the oncoming car for several seconds before the crash occurs.
 * Motherhood Is Superior