When Des has another ‘out-of-body' experience, in which he saves Miss Griffin and her crew from an attack by the Xux, Netta becomes concerned that her husband was calling out the name of one of his customers in his sleep. The next morning, Netta resolves to pay more attention to Des, and begins by taking an interest in his hobby of U.F.O. spotting. Later, an irate Miss Griffin arrives at the shop – it seems that the duplicate key Des made for her has snapped in its lock, and now she wants the inept repairman to visit her flat and fix things. While her husband is away with the attractive Miss Griffin, a worried Netta soon encounters Anthony Jessop, a suave representative from the Education Department, who is conducting surveys in the area. Taken in by the handsome man's charms, Netta decides to ask Jessop round for tea that evening; however, when her husband hears that Jessop was asking strange questions, showed an interest in Des' U.F.O. newspaper, and came from the Town Hall, Des and Jim suspect him to be a Xux humanoid – and that the aliens may also have replaced Netta with a duplicate…