Fifteen-year-old Daniel X is not an ordinary human boy. He is a highly intelligent alien with superior strength, speed and the ability to create and transform objects as well as teleport himself from one place to another. Daniel is also an alien hunter, following in his parents' footsteps. He is going after a list of alien criminals on Earth. When Daniel was a toddler, an alien criminal called "The Prayer" killed his parents. Daniel's ultimate goal is to kill this alien — No. 1 on the "List of Alien Outlaws."
Daniel is now targeting No. 5 on The List, his most formidable opponent yet. No. 5 is a catfish-like, technologically advanced alien who uses electronic devices to control the thoughts and actions of humans. He is also a film director, who uses humans to perform dance routines and act in scripted scenarios. He then kills the humans while filming, all for the purpose of broadcasting these shows to aliens across the cosmos. He calls this programming "endertainment."
Daniel follows No. 5's scent to the town of Holliswood, where he finds a diner that has been trashed by the alien and his henchmen. Left behind are the remains of vaporized police officers and a brainwashed, unconscious waitress, Judy.
Daniel helps Judy recover and clean up the diner. She tells him that Holliswood is a small, quiet town. Guided by his senses, Daniel leaves the diner and enters the local superstore, where he notices that almost all the adult women in town are pregnant. He follows several women into another building, a supermarket, and finds the aliens filming. When Daniel and the aliens start fighting, Daniel is knocked out. To his surprise, he is not killed but is left to recover.
After Daniel uses his imagination to materialize his family and friends, they help him investigate No. 5's activities. He discovers that the local television station has been sending packages of caviar to all the adult women in Holliswood, so he goes to the television relay station to learn more.
On the way to the station, Daniel and his friends notice a stray dog with alien burn marks. They also see that the windows of every house glow with the blue flicker of television or computer screens. They discover that aliens have taken over the television relay station and are using its signal to broadcast No. 5's endertainment to aliens across the galaxy.
When Daniel takes the dog to the local animal shelter, he's told that several dogs in town have been found with burn marks. They've been howling in the direction of a local farm, where there has been unusual activity. Daniel stakes out the farm and discovers that No. 5 is using the women of Holliswood to incubate his offspring. The women are brainwashed into eating fish eggs, and the larva incubate in their stomachs. Daniel sees a woman vomit the baby aliens into a pond at the farm. He also finds No. 5's plans, revealing that Holliswood is the first town to be invaded by the aliens. No. 5 intends to take over the planet, and Holliswood is just his pilot episode — a preview of what he has planned for the rest of Earth.
Daniel returns to the diner to talk to Judy. Once inside, he notices some of No. 5's henchmen in disguise, so he throws hot coffee on them and runs into the parking lot. The henchmen unleash an alien creature with the body of a 600-pound lion and the head of a giant ant. The creature has been conditioned to hate Alparians, Daniel's species, and so it attacks him. After Daniel turns himself into a giant creature that is a cross between an elephant and a spider, he subdues the ant-lion with a giant spider web and reprograms the creature to hate No. 5's henchmen instead. Once released, the beast goes after the other aliens.
Noticing that the townspeople are staggering toward the farm as they stare at their cellphones or other portable electronic devices, Daniel and his friends decide to confront No. 5 at the farm. In addition to using the women as incubators, No. 5 has been using the people to dig the ponds on the farm. After he kills the people, he uses them as fertilizer. Daniel's friends attack No. 5 and his henchmen, and Daniel notices that No. 5 has transparent screens over his eyes that constantly feed him data.
No. 5 taunts Daniel by telling him that he was there when The Prayer killed Daniel's family, and he can prove it by the silver necklace that Daniel's father always wore. No. 5 also tells Daniel that he wasn't planning to kill him just yet, but he may have changed his mind. Daniel dematerializes his friends and teleports himself back to his house for a strategy session.
They discover that No. 5's ability to broadcast himself to electronic devices and see out of television screens is made possible by a surgically implanted computer system within his body.
With this knowledge, Daniel and his family return to the farm where they find No. 5 waiting for them. A storm is brewing, and Daniel decides how he will use it to his advantage. Another fight ensues. At first, Daniel and his friends hold their own, but they soon realize that the aliens outnumber them, so Daniel surrenders. No. 5 tells Daniel that his death will entertain trillions of aliens.
Just as Daniel tries to figure out what his next step is, one of his friends, Emma, comes charging in with the ant-lion and a pack of dogs from the animal shelter. During the commotion, Daniel asks No. 5 to show him his father's necklace, which Daniel joins with his own. Daniel cries, and as No. 5 embraces him (only to provide more drama for his show), Daniel holds up the silver necklaces and attracts a bolt of lightning, overloading No. 5's circuits and killing his body.
With No. 5 dead, and with the help of the dogs and the large ant-lion, Daniel wipes out No. 5's army. While driving back home from the fight, Daniel learns that the virtual version of No. 5 is still alive in electronic devices. The group loads up all the electronic devices in town and dumps them into the breeding ponds on the farm, effectively killing No. 5.
Daniel then uses No. 5's mind-control broadcasting techniques to erase the memory of himself and the aliens from the memories of everyone in town. After cleaning up the town and getting things back to normal, Daniel leaves. He decides to go after No. 3 on The List, an alien whose body is 70 percent fire.