Create Milo (Seth Green), her mother is the most annoying person in the world. Milo was no longer able to live with any rules made ​​by the mother. Disposing of garbage, should eat vegetables and many more rules which, according to Milo's not important. But as they say, something sometimes appear worthless until we no longer have it.

Without the knowledge of Milo, was a creature from the planet Mars which actually requires a mother and intends to take Milo's mother could care for their children. Instantly Milo panic. He must save his mother. He did not know how but importantly he must find his mother and save her from the aliens. Clearly the effort was not an easy business. Fortunately Milo is not alone.

With the help Gribble (Dan Fogler), a technology expert and the Ki (Elisabeth Harnois), who have the nature of Mars girl rebelled, Milo started interplanetary adventure to save his mother. To achieve that goal, Milo inevitably have to fight The Supervisor (Mindy Sterling), which controls the entire planet Mars.