For centuries, interstellar prospectors had searched for the fabled worlds of the Three Kings, the lost El Dorado of the galaxy. But if any found it, they were never heard from again. The mad cyborg Prophet, Ishmael Hand, discovered the mysterious system, with artefacts indicating a superhuman technology, and he had refused to reveal its location before vanishing. Now a chance encounter between what's left of the once - mighty human military and an inexplicable allen force has brought an armed expedition to the third planet of the Three Kings, Kaspar. They will join forces with the survivors of the two earlier expeditions, who have been marooned both by alien powers and by human treachery, as they at last encounter the alien minds behind the mysterious triple planetary system - and they will face a decision that may determine the fate of the entire human race!