So here's the thing about suspension of disbelief in movies: We can buy that, say, giant robot aliens can turn into tractor-trailers, but the human characters have to react in a way that makes sense.

So here’s the thing about suspension of disbelief in movies: We can buy that, say, giant robot aliens can turn into tractor-trailers, but the human characters have to react in a way that makes sense.

“I Origins” is not silly summer escapism. It has some deep thoughts about spirituality vs. science, but that brain-teasing premise only magnifies a questionable love story at its core.

Ian (Michael Pitt) is a molecular biologist who is doing some important research on the eye. He has a thing for eyes, as we discover when he meets Sofi (Astrid Bergès-Frisbey) at a costume party. She’s wearing a ski mask, but that’s OK for Ian. “Can I take a picture of your eyes?” This is apparently not creepy to Sofi, as they (almost) hook up immediately thereafter.

Ian didn’t get Sofi’s digits, but, man, is he into her! “You ever feel like when you meet someone they fill a hole inside of you and when they’re gone you feel that space so painfully vacant?” Sure, Ian.

Via some wild coincidences and some not coincidental internet stalking, Ian reunites with Sofi, and they have naked philosophical discussions and then he asks her to marry him after, like, a week. And then a tragedy befalls them that will eventually lead back to Ian’s eyeball research.

This love story is only a portion of the movie, but it’s so important to what comes after — and is so lazily handled — I found it tough to overcome the eye rolls. Sofi looks like a model and has an undetermined European accent, but the “love at first sight” approach isn’t enough of a foundation for Ian’s actions that follow.

Director Mike Cahill (“Another Earth”) is still good with atmosphere, and his “Earth” star Brit Marling is great as Ian’s research assistant. But Pitt’s detached performance seems wrong for his struggle.

The eventual payoff is a chin-scratcher. If you’re looking for a better way to be baffled, check out Scarlett Johansson in the recent “Under the Skin.” This one still needs to evolve.

Photo courtesy of Fox Searchlight