Attempting to prove his theory that what the world always needs is a hero, Danger Mouse fights off what appears to be an alien invasion of Earth but his inflated ego soon becomes the real intergalactic threat! The alien invaders are tourists led by Quark and DM's impressive performance in sending one tour packing, soon leads to millions more arriving. Danger Mouse becomes the most popular tourist attraction in the universe. Visitors flock to earth turning it into a massive Danger Mouse inspired theme park. It's up to Penfold to save the world by convincing Danger Mouse that what the world needs right now is a... coward!?