A regular summer day in Danville takes a wild, extraterrestrial turn when a UFO suddenly crash-lands right in the backyard! Phineas and Ferb are always looking for the ultimate summer project, but this time, the adventure literally falls from the sky. Meet Meap: an adorable, big-eyed alien pilot who looks more like a cuddly pet than an intergalactic explorer. But there is no time to just hang out with their new friend. When Phineas, Ferb, and Isabella decide to take Meap's spaceship for a quick joyride, they accidentally blast off into space and straight into the clutches of Meap's arch-nemesis, the villainous Mitch. Suddenly, the kids are trapped inside an alien prison, and their only hope for rescue lies with the unlikeliest team in the universe. It is entirely up to Candace—who was just trying to show off her cute new discovery—and the surprisingly brave Meap to mount a daring space rescue. Get ready for an out-of-this-world cosmic comic adventure filled with the classic humor and fast-paced action you expect from your favorite stepbrothers. Will they defeat Mitch and make it home before dinner?