1 And Then There Were 10

10-year-old Ben Tennyson begins summer vacation with his paternal cousin Gwen and their parental grandfather Max. During a trip to Yosemite National Park, he wanders off and finds an alien pod that has crashed to earth, and within it a watch-like alien artifact. When he reaches to touch it, the watch jumps onto his wrist and refuses to come off. Ben accidentally discovers that it can change his form into various alien creatures and quickly learns how to use it, protecting people from robots sent by Vilgax, an alien conqueror who plans to use the watch to equip an entire army under his control with its powers. Deciding he can be a real-life superhero, Ben begins a summer full of extraterrestrial adventures for himself, Max and Gwen.