They say the best stories refuse paraphrasing, that they have an indescribable quality, that a simple summary can’t capture whatever feeling they impart on their audience.

“The Space Between Us” is easily summarized. Gardner Elliot (Asa Butterfield) is the result of a scandalous accident, born to an astronaut on a Mars mission. He grows up on Mars, a secret from the world and physically unable to handle Earth’s stronger gravity. After a risky surgery to strengthen his bones, he’s brought to Earth and quarantined to have his health monitored. Of course, he immediately, unbelievably escapes to track down the girl he’d been cyberchatting from Mars and the person he thinks is his father.

“The Space Between Us” is not a story. It’s a concept, a single idea: “What if a Martian kid came to Earth for the first time?” Everything else in the film feels like a rapidly half-baked attempt to build something, anything around that premise. Unsurprisingly, nothing that writers Allan Loeb, Stewart Schill and Richard Barton Lewis have come up with holds any weight. Realistically, it isn’t actually sci-fi; space is just a plot device with marginal lip service, which is a shame.

The plot is weak at best and utterly unbelievable at worst. Just the number of cars that Gardner and his love interest Tulsa (Britt Robertson) steal while crossing the country and being chased by authorities with superior technical sophistication and resources is absurd. In fact, all real, possible obstacles to the teens’ journey are brushed aside as if the characters exist in a magical world where a benevolent god is tuning reality just for them.

Speaking of characters, for the most part, there aren’t any. Gary Oldman tries his best as an Elon Musk/Richard Branson-like figure who organizes the first Mars mission, but can’t go because of a possible medical issue. It’s also painfully obvious from the start that he’s involved in the major plot reveal. His first lines, a speech to a crowd of donors, are cringy and contrived. That’s okay, because such speeches usually are anyway. Unfortunately, though, his character never extends beyond the range of those opening words. One could fit his whole schtick of a personality on one side of an index card.

Kendra (Carla Gugino), an astronaut who raises Gardner on Mars and helps track him down on Earth, is just as one-dimensional. Her character exists only to further the plot and, ultimately, her reactions are wholly unrealistic. Upon finding her young charge driving donuts in the rover outside the base — don’t ask for a shred of scientific realism here, folks — and watching him flip, break the rover and almost die, she yells at him for about two seconds in the airlock and then pretends the whole thing never happened. Not very motherly.

The one shining point in the film is Asa Butterfield’s acting — in particular, his beguiling reactions to “Earth-things” such as rain or dogs. In fact, the best advice for this movie would’ve been to just throw the whole thing out and start over with Butterfield and a different writer. But despite his acting strength, this script leaves him utterly unknowledgable of human customs, at odds with his clear intelligence earlier in the film, as if he wouldn’t have Netflix on Mars to “learn of the humans.”

The romantic through-line of Gardner with his cyberfriend is predictable and usually cringe worthy in its soppiness. Like every other relationship in the film, it’s shallow and one-dimensional, a fault primarily of the script rather than the acting of Butterfield or Robertson.

Ultimately, an unrealistic, undriven plot and uninspired dialogue sink the decent performances by Butterfield and Robertson. We root for them to find a foothold somewhere in the plot — and for their next line of dialogue to move toward depth — but it just never happens.

Oh, and it doesn’t matter how far in the future this is. There’s an average 12 minutes — maximum 24 minutes — of light-travel time delay with Mars. Those instantaneous, HD video communications between Mars and Earth that are all over this movie? Stop that.

“The Space Between Us” is currently playing at UA Berkeley 7.