An alien spaceship identifying itself as EARTHSHIP VENUS 5 instructs the Jupiter 2 to activate its landing beam. At first they are refused, but in the absence of John, Don and Maureen, the craft is eventually allowed to touch down on the planet, under the guise they are space tourists looking to enjoy a short-term vacation.
Dr Smith senses a lucrative business deal in the making. He negotiates with the aliens representative Mr Zumdish to host the alien holidaymakers in return for cannisters of deutronium.
In short time, Smith converts the Jupiter 2 into a holiday resort. He names it HAPPY ACRES HOTEL. Its motto is – “A happy guest is a paying guest”. Attempting to talk-up the fun times that await guests, Smith gushes to Zumdish –“This is the gayest resort in the galaxy”.
Dr Smith begins referring to the Jupiter 2’s rooms as suites and enlists Will to serve as a dutiful bellboy. The robot and Will do all the work – tending to the guests, feeding them, making sure they are entertained and their every need is met. Dr Smith gives the orders, including this classic for the breakfast menu, “Remember, plenty of water in the fruit juice and no seconds for anyone”.
The next night, on a full moon. the holiday makers transform into their more frightening alien form. Fearful they will be discovered, they make plans to do away with their hosts. But at dawn they revert to their human form. The next night the same thing happens.
Smith is seduced into wearing a ring by one of the female aliens. When the sun goes down, still wearing the ring, he too briefly transforms into a werewolf type creature.
When Don, John and Maureen return they are shocked to discover the Jupiter 2 has been transformed into the holiday resort HAPPY ACRES. Don and John overpower the aliens. Zumdish departs accompanied by one female ‘holiday maker’.