The Boov have a problem. Every time their archenemies, The Gorg, find them hiding somewhere new in the universe, The Boov have to run away to a new host planet. And this time, their destination is Earth. The humans -- including seventh grader Tip (voiced by Rihanna), who ends up separated from her mother, are less than thrilled as The Boov vacuum them up and send them to Australia. But Tip makes an unlikely friend in Oh (Jim Parsons), an unusually friendly Boov who craves a connection. Despite a rocky start, the two form a bond, and together they conspire to find Tip's mother and -- naturally -- save the planet.