Synopsis: From the front flap of Gollancz first edition: "It was a bizarre and beautiful invasion. Suddenly the Foreigners were everywhere: walking the streets of 21st century earth as if they had been there all along; their inscrutable golden masks floating above the crowds on top of their seven foot robe clad bodies. They brought with them the technological marvel of Crystech at once a power source and a building material; it banished all our worries and heralded a new utopia. All they asked of us was that we sing to them. All they threatened was that one day they might leave and take Crystech with them throwing us back into the dark ages. And now, in a hotel room on one of the gleaming white streets of New Venice, one of the Foreigners has been murdered. And if we cannot find out who killed it before another dies then the Foreigners will go giving us back disharmony and, perhaps, freedom."