They had landed on the forbidden planet of Boroq-Thaddoi. They had made their way across the snow-covered desert and the vast graveyard of mangled spaceships. Now they stood gazing with awe at their destination, the Citadel. The Citadel was unique in the galaxy. Some mad, brilliant architect might have dreamed this blending of the arts and materials of a hundred civilizations into a single monstrous edifice, but no known race could have erected such a thing. It dwarfed the nine walls of Skix, the great corridor on Clotho, the ageless pyramids of Xhanchos, even the legendary cities of Old Earth in the proud and violent centuries before the exodus. It was the monument of giants. Somewhere is the perilous labyrinth behind these towering walls lay the secret that had eluded and destroyed all searchers for thousands of years. . . the secret that had to be found before the Great Rebellion could begin. . .