One thousand years after mankind abandoned Earth, a spaceship crashes on the planet, killing everyone aboard except the commanding officer Cypher (Will Smith) and his teenage son Kitai (Jaden Smith), who is trying to live up to his father’s legendary military record. As Cypher’s leg is broken, he can’t walk, so Kitai must venture outside by himself, find the tail of the shattered vessel and obtain a homing beacon that will send help.

But in the ensuing years since human beings bailed, all animal life on Earth has mutated into snarling beasts, and they exist only to kill. There are also some enormous alien monsters who attack their prey when they sense their fear. Cypher has learned the ability of “ghosting,” which means never being afraid. His son, though, isn’t quite there yet.

Much of After Earth follows Kitai on his adventure through this perilous planet, dodging hungry gorillas, lions and snakes while following his father’s orders via an intercom he wears on his wrist. The movie was directed by M. Night Shyamalan, whose career has hit a bit of a rough patch ( Lady in the Water, The Last Airbender, The Happening), but he retains his sense of great composition and a strong grasp of narrative told primarily through visuals.

But even though he co-wrote the screenplay, Shyamalan isn’t the star this time. After Earth belong to the young Jaden, who holds your attention despite being the only person on screen for long stretches of the film. Instead of playing the character as heroic, Jaden conveys terror, fear and awe, often without dialogue. He’s a gifted actor who will get even better with time.

Too bad he’s forced so often to “take a knee,” as his father does when he needs to calm down, an action that bears an uncanny resemblance to Tebowing (OK, it’s the exact same thing). Too bad, too, that the CGI creatures in the film look as fake as the monkeys in Indiana Jones and the Kingdom of the Crystal Skull: Every time a dangerous critter pops up, you’re taken out of the movie as if you’d just hit the eject button on your seat. Even worse, the story doesn’t make much sense: In a thousand years, wouldn’t all the surviving animals, rabid and savage, have had already killed and eaten each other?

After Earth, which is pitched squarely at fathers and their 12 year-old sons, is never awful — you don’t laugh at it the way you did with some of Shyamalan’s other pictures — but unlike the recent Oblivion, which at least threw out a couple of plot twists after the premise was established, there’s nothing more to this movie than the set-up. Even though Cypher is slowly bleeding to death, and Kitai is running out of oxygen capsules that allow him to breathe in the toxic air, there’s no sense of urgency, either. At least Shyamalan, sensing the thinness of the material, doesn’t stretch things out. After Earth gets the job done, but he didn’t exactly set a high bar for himself.