Ben Tennyson, a 10-year-old soccer athlete from the city of Bellwood, begins summer vacation on a cross-country road trip with his parental grandfather Max in the latter’s RV (the Rust Bucket), but is livid when his smart-mouth twin cousin Gwen comes along. While camping at Yosemite National Park, Max tries to cheer up his grandchildren with camp-based activities, but neither will participate and Ben wanders off into the woods. Meanwhile in space, Vilgax, a Chimera Sui Generis warlord regarded as one of the most feared beings in the Milky Way, is commandeering his warship (the Chimerian Hammer) in pursuit of a small courier ship carrying the Omnitrix, intent on using the device to equip an entire army under his control. The deflector shields on both ships are disabled as the battle reaches Earth’s orbit, allowing the courier to blast the Hammer’s main bridge and cripple Vilgax. Before most of it (except the main bridge) is destroyed by returning fire, the courier ship jettisons the Omnitrix in a special pod, which falls to Earth and crash-lands in Ben’s path. Ben investigates the pod, and the Omnitrix jumps out and fuses to his left wrist. After several attempts to get it off, he transforms into a Pyronite (dubbed Heatblast) and accidentally starts a forest fire. Max and Gwen notice the smoke from their campsite and advises him put out the fire out with a back-draft. Once all is explained back at the campsite, Max orders his grandson against playing with it while he searches for answers. Confined to a healing chamber, Vilgax sends a giant drone down to the crash site, where it destroys the pod and launches two smaller drones to search the area. The drones attack Ben as he is exploring the forest as a Vulpimancer (dubbed Wildmutt), leaving Gwen to save his life by destroying the other with a shovel. Later, Max’s lecture to Ben is interrupted by a park ranger radio report about the giant drone attacking the RV camp nearby. The Tennysons head over to the scene, where Ben fends off the robot as a Petrosapien (dubbed Diamondhead) while Max and Gwen bring the civilians to safety. Although losing, he goads the drone into firing a laser at him which he redirects, destroying it with its own blast and disappearing into the forest as the civilians look on. A furious Vilgax swears vengeance, vowing to destroy the Omntrix’s new host as soon as his strength returns. Determined to get revenge against his school rivals JT and Cash Murray, Ben races back to Bellwood as a Kineceleran (dubbed XLR8) and hangs them from a tree by their underwear. Returning to Yosemite the next morning, he quickly helps Max and Gwen pack up the Rust Bucket, and all three Tennysons drive off, starting a summer vacation filled with extraterrestrial encounters and heroism.