If you’re going to make a movie about cloning a dead kid, and how weird stuff starts happening once Kid 2.0 reaches the age where Kid 1.0 died — well, if you’re going to do that, you have to expect that things are going to get silly. Absurdity is probably inevitable when you join the subjects of creepy kids and technology.

This will be of little consolation to the people behind “Godsend,” who evidently thought they were making a suspenseful and dread-inspiring cautionary tale but who made a ridiculous movie instead.

Its first two-thirds are good enough, actually. Paul and Jessie Duncan (Greg Kinnear and Rebecca Romijn-Stamos), a biology teacher and a photographer, are happily raising their perfect son Adam (Cameron Bright) in a big city somewhere. But the day after his eighth birthday, Adam gets nailed by a car, and whoops! So much for that perfect life. Better luck next time, Duncans.

Ah, but there IS a next time! Richard Wells (Robert De Niro), a former professor of Jessie’s, shows up just after the death to propose a zany scheme wherein Adam’s DNA and a few cells are used to make a new baby, which Jessie will carry to term, give birth to, and presto! Adam 2.0, fresh out of beta-testing and ready for use. Paul thinks the idea is madness — MADNESS, I tell you! — but gives in to Jessie’s wishes to just have her son back. Or a new son who looks just like the old one, anyway.

So it happens, and the kid gets to be eight years old, and he passes the point where the previous Adam died. That’s when things start to get freaky. Director Nick Hamm gets good play out of Adam’s nightmares, particularly one where he sees a screaming reflection of himself in a window. Could he be “remembering” his past life? Is that even possible? Is ANY of this possible? (Don’t answer the last one.)

The screenplay, by Mark Bomback, starts to stall in the third act, though, constantly hinting at horrible things to come without actually letting any horrible things come. We begin to realize the film is more bluster than substance, as it keeps putting off the inevitable manifestation of Adam’s new-found evilness.

Alas, when it does finally get to where it’s going, it rushes over the edge and into the pit of lunacy, the characters fulfilling their destinies with requisite screaming and melodrama while assorted nefarious secrets are revealed. The unsatisfying ending, which shies away from where the very dark places the story was REALLY going, is the result of Lions Gate sending the film back for reshoots last fall, and while I can only guess what the original ending was, surely it was better than this one.

Still, I kinda liked the first hour or so — not in a “Wow, this is good” way, but in a “Hey, this isn’t so bad” way. Within the genre of dumb movies that think they’re really smart, it’s better than some.

C (1 hr., 42 min.; PG-13, a little profanity, some brief sexuality.)