Des' repair shop was left to him by Netta's late father, and so he is less than pleased to receive a rates demand for the property. Learning of Des' predicament, the overbearing Miss Griffin forgoes complaining about his lack of progress at fixing her broken hair-dryer, and bullies him into standing up for himself by complaining to the local Town Hall. However, when Des arrives at the Bingleton Borough Council offices, his protests are promptly ignored by the pompous Mr Horsley, who threatens to carry out a full assessment on the premises if Des refuses to pay up. Defeated, Des returns to his shop and meets Jim, who attributes his friend's lethargy to ‘culture shock', caused by his recent close encounter with Miss Griffin and her alien crew aboard their spaceship. In desperation, Jim takes a dose of his late father-in-law's collection of old health-tonics – the shock of which inadvertently causes him to astrally transfer himself across space to Miss Griffin's side, arriving on the bridge of her flying saucer. Together they travel to the planet Mercury, where Des is introduced to the wise elder, Buddo, and learns of a grave danger threatening the Earth: it seems that an alien race known as the Xux is infiltrating the planet by replacing humans with their own evil android duplicates. Des immediately realises that he has already met one of these humanoids: none other than the council's Mr Horsley…