Where do the metal death gliders come from? To the glass-sailors of the five villages the slow birds that inched over the Earth at shoulder height, appearing and vanishing, were a mystery - until young Daniel climbed aboard one of the scarred Missiles and vowed to find out where it went

Ian Watson's third short story collection is his best yet: a brilliant array of original and imaginative inventions that plunge the reader into strangely familiar new worlds.