The master computer of the planet Harmony was not designed to interfere so directly in human affairs. It was deeply disturbed by the fact that it had just provoked young Nafai to murder Gaballufix. But how could the master computer return to Earth without the Index? And how could Nafai have got the Index without killing Gaballufix? There was no other way.

Or was there? I am old, said the master computer to itself. Forty million years old, a machine designed to last for nowhere near this long. How can I be sure that my judgment is right? And yet I caused a man to die for my judgment, and young Nafai is suffering the pangs of guilt because of what I urged him to do. All of this in order to carry the Index back to Zvezdakroog, so I could return to Earth.