"Purple!" Mark Denning almost sobbed. "A purple Josmian!" Forgetting the sweat in his eyes and the insufferable heat about him, his clutching hand held up the mud-dripping globe the size of a baseball, iridescent in the Venusian night. The phosphorescent glow that bathed the endless swamp in ghastly green, struck myriad shimmering rainbows from the dark sphere. "Two more of those and you're free, lower species!" It was an ironic voice, with the resonant sweetness of a cello in its depths, that i