The robots loved flying around on the rocket so much that they've decided to play on the Moon. Lea and Leo are watching the robots from their communication tower. Something's gone wrong. The robots are stuck in the crater and can't get out. They need help right away. Leo has an idea: they can build the robots a lunar rover. That's a very special vehicle made for moving around the Moon. With the lunar rover the robots will be able to research the Moon's hardest-to-reach parts.