robots and linked them with a complex computer. The computers designed ever more advanced robots, which built even more sophisticated computers. In the end, the physically perfect androids achieved sentience, learning human characteristics through observation—then enslaved the human population. They want to eliminate their creators, but they have never been exposed to anger or hatred, and thus cannot kill. The masks prevent the Vegans from seeing strong emotion should the humans let down their guard. Eight warns the Alphans to be wary: the androids will try to entice a demonstration of violence...then kill every last one of them. While investigating the computer chamber, Verdeschi and Helena discover it is protected by a powerful energy barrier impervious to laser fire. Zarl and Zamara appear, reproaching them for leaving their 'quarters'. The Alphans' excuse is they are worried about their friends on the Moon and are trying to return there. The androids tell them to simply desire it. They do, and find themselves back on an Alpha that is powered up and running—and apparently deserted. A quick search proves they are the only two people present. Worse, calculations show the Moon is now two light-years distant from its previous position in the Vega system; they must have travelled through a time warp during the positronic transfer and arrived weeks in the future. They can only speculate the rest of the Alpha population was taken down to the planet. When they try to wish their return to Vega, nothing happens—the process has apparently been turned off. They are, in fact, in a replica of Alpha. By isolating them, the Vegans intend to foster suspicion, paranoia and murderous rage between them. (Zarl finds the procedure cruel, but is convinced of its necessity by Zamara.) Using circumstantial evidence, they manoeuvre Helena into believing the security chief gave her a drugged coffee. Verdeschi is then made to assume the doctor sabotaged the life-support system. This exercise in psychological warfare ends with the two friends hunting each other with lasers set to kill. Thinking the other is unbalanced, each tries to humour the other. Finally, realising that neither is responsible for the deeds the other accuses them of, they recognise the situation for what it is. As the two gloat over their victory, the androids come out of hiding and Zamara admits failure—this time. On Alpha, the temperature is below freezing and the air stale and dank.