Take out the trash, eat your broccoli - who needs moms, anyway? Nine-year-old Milo finds out just how much he needs his mom when she's nabbed by Martians who plan to steal her mom-ness for their own young. Milo's quest to save his mom involves stowing away on a spaceship, navigating an elaborate, multi-level planet and taking on the alien nation and their leader. With the help of a tech-savvy, underground earthman named Gribble and a rebel Martian girl called Ki, Milo just might find his way back to his mom - in more ways than one.