The events of Heads are set on the moon about two centuries in the future. It is inhabited by two million people, all allied with one of more than fifty families, called "multiples." The major action takes place in the Ice Pit, "a volcanic burp in the Moon's ancient past, a natural bubble almost ninety metres wide that had once been filled with the aqueous seep of a nearby ice fall." The ice has long since been mined for water for the inhabitants of the moon, and the Ice Pit is used mostly for an unprofitable farm and the experiments of William Pierce, who is trying to reduce the temperature of some copper to absolute zero. He is an in-law of the Sandoval family, the multiple that owns the Ice Pit, and his work is funded partly to keep his wife happy, partly to give the novel's narrator...