Mole has proof that his Sea Monkeys are official, government, top-secret Sea Monkeys that are mutating in his fish tank. Mutated brine shrimp have escaped from NASA. Pretending to be Sea Monkeys, the shrimp are hiding out in a fish tank in Mole's room. They have a secret mission: they must build their space ship: then use it to go back to NASA to rescue the ones left behind: and then they must escape Earth and the Men-in-Black. Problem: The Men-in-Black have discovered that the brine shrimp are being held in a boy's room. They must get back the shrimp and then decide what to do with the kids that have stolen top-secret government property. Now, it is up to Mole and Skull to protect the shrimp and help them rescue the ones left behind.