GIL, the computer, has a terrible crash and Mum calls a technician out to the Moonbase. But without a working computer, she can't get her work done so Cosmo suggests they take a holiday. After a misunderstanding, the whole family head to planet Venus, the hottest planet in the Solar System. But the weather on Venus soon takes a turn for the worse – heat, wind and even acid rain! Cosmo must help the family find some place to take shelter, all the while enjoying what she calls the best holiday ever!