John Smith is an alien from the planet Lorien. He was sent to Earth as a child with eight others, collectively called the Garde, to escape the invading Mogadorians, who destroyed Lorien. John is protected by a guardian (who are known as Cêpan), Henri, and has developed powers, including enhanced strength, speed and agility.
The Mogadorians, led by Commander Setrakus Ra, learn about the nine children and travel to Earth. The Garde can only be killed in sequence; Number One through Number Nine. Three of them are already dead, with John being Number Four. Knowing this, he and Henri move from a beachside bungalow in Florida to an old farm in Paradise, Ohio, where John befriends conspiracy theorist Sam Goode and a Beagle which he names Bernie Kosar. He also falls for an amateur photographer, Sarah Hart. Her ex-boyfriend, football player Mark James, is a bully who torments both John and Sam.
During the Spring Scream Festival, Mark and his friends chase Sarah and John into the woods. When they attack, John uses his powers to fend them off and rescue Sarah. Sam witnesses this, which leads John to reveal his true origins. The next day, Mark’s father, the local sheriff, interrogates Henri on John’s whereabouts when his son and his friends were attacked. Henri tells John that too many people are suspicious and they have to leave. John refuses because of Sarah.