Children with paranormal abilities, love of nature, dread of adult ruthlessness, compassionate adults, tense chase sequences, dramatic paranormal escapes and isolationist communities living apart from ordinary society are all hallmarks of the juvenile science fiction of Alexander Key.

All these themes are at work in Key’s best-known story, the 1968 novel Escape to Witch Mountain, the basis for the highly successful 1975 Disney adaptation, as well as a theatrical sequel, two made-for-TV follow-ups, and now Race to Witch Mountain.

I first read Key’s Escape to Witch Mountain in about the fifth grade, I guess — after the 1975 Disney adaptation had been made, but before I saw it. The story stuck with me, in part, I guess, because in some ways, I related to Tony and Tia: I was gifted in my own way, but somewhat isolated from my peers and misunderstood, among other things.

I mention this to highlight how substantially Race to Witch Mountain departs from its creative roots.

Publicity materials call Race a “modern reimagining of Key’s book,” and director Andy Fickman has called it “a new chapter within the world of Witch Mountain,” but neither description is really accurate.

Yes, there are still a brother and sister with paranormal abilities (and alliterative names) fleeing from ruthless adults and aided by decent ones. And there are still tense chase sequences, a dramatic paranormal escape and a strange, remote community.

There’s still a Witch Mountain — and a Stony Creek — though the Witch Mountain connection is completely different. There’s even a white-haired old man who drives a Winnebago motor home, like in the first movie, and a jaded taxi driver with race-car affinities, like in the sequel.

However, the focus is no longer on the paranormal siblings, here reduced to supporting characters. Nor does it deal with their exploration of their powers and origins.

Instead, it’s the story of a tough Vegas taxi driver named Jack Bruno (Dwayne “The Rock” Johnson), whose day takes an unexpected turn toward disaster when a pair of steel-eyed blond children appear in the back seat of his cab.

“We require your transportation services immediately,” the boy says urgently, and the girl helpfully adds, “You require a financial transaction, Jack Bruno. We understand.”

As the rapid-fire, quasi-Vulcan speech patterns suggest, siblings Sara and Seth (AnnaSophia Robb and Alexander Ludwig) are not aimless orphan castaways searching for home, but rather strange visitors recently arrived.

Jack’s profession and stock-car racing past recalls the race-car wannabe taxi driver from Return to Witch Mountain, but Jack’s disposition — testy and wary of becoming entangled with the children, but ultimately loyal and brave — is more like Eddie Albert’s crusty old Winnebago driver from the original movie. Just with bulging muscles, a lantern jaw and an attitude.

Scarcely has Jack picked up Sara and Seth when his taxi is beset by a trio of ominous dark SUVs in the Arizona desert.

Jack, an ex-con determined to sever his ties to organized crime, believes their assailants are mob muscle, but the siblings know there’s more going on, and before long, display some tricks Tony and Tia never even dreamed of.

They also face greater threats: Besides government pursuers led by Ciarán Hinds, there’s also a faceless, armored alien menace called the Siphon.

On the other hand, they’re also aided by disgraced astrophysicist Dr. Alex Friedman (Carla Gugino of Watchmen and the Spy Kids franchise), whose views on extraterrestrials have made her persona non grata in the scientific community, and by eccentric UFO convention regular Dr. Harlan (Garry Marshall), who drives a familiar-looking Winnebago.

The plot ultimately requires the heroes to break into a top-secret government facility at Witch Mountain, Ariz., to recover a captured UFO. (In the previous films, Witch Mountain was the site of a secret settlement of Tony and Tia’s people — a change that makes it difficult, if not impossible, to locate this film in the same world as earlier Witch Mountain stories.)

Rather than a coming-of-age story, then, Race to Witch Mountain is a dark family action-adventure movie, with moderate doses of X-Files paranoia and Galaxy Quest sci-fi fandom satire. It’s slicker, darker and funnier than the original films, though wall-to-wall action makes it a bit of a one-trick pony and prevents the characters from catching their breath and displaying more than one side.

Seth is intense and narrow-eyed and has a withering view of humans. Sara is sensitive and gazes meaningfully through wide eyes; she either wants to tell Jack something extremely important or else just has a crush on him.

Jack is gruff and fatalistic and goes through the movie dealing with the craziness by tossing off deadpan one-liners for nobody’s benefit but his own.

At times, Jack’s wry commentary even defuses some of the movie’s more dubious moments. He does miss a few tricks, though: If Sara can blow up government vehicles to prevent pursuit while fleeing a small-town tavern, why couldn’t she take out the SUVs in the desert road sequence — or even the Siphon’s spaceship?

Witch Mountain fans will get a kick out of that small-town tavern scene, in which Sara and Seth are aided by a helpful waitress and a quietly self-assured sheriff played by Kim Richards and Lake Eissinmann, the original Tony and Tia. (On another level, Second Amendment fans will appreciate a humorous demonstration of the benefits of a well-armed civilian populace.)

But the perfunctory plot mechanics detract from the Witch Mountain mythology rather than adding to it. Spoiler warning: Do we really need our heroes’ homeworld contemplating invading Earth as their own planet is dying, even sending nearly unstoppable alien assassins to our world to kill two of their own?

First The Day the Earth Stood Still — another sci-fi remake-cum-eco-parable, with a less-than-enlightened Klaatu — and now this. Whatever happened to the noble aliens?

Steven D. Greydanus is editor and chief critic at DecentFilms.com.

Content advisory: Much intense action violence; menace to children. Too scary and intense for kids under 10.