Meditatively, he raised the fragile Bacca-glass to his lips and sipped the fiery liquor that Ionians distilled from the fragrant stems and leaves of the _Clavile_ plant. For days, his mind had whirled in hopeless circles, and he wondered with a curious sense of detachment, whether he wouldn't be better off to leave the problem to the scientists. Only, it was his duty as much as any scientist, to search for clues. Julian raised his eyes and gazed at the great tiers of stars that glittered above the towering, purple crags of the _Mallar_ range. Throughout the hours of the Ionian night, the skies had been peopled by the singing of these constellations. But there had been none to hear it, for despite the ravages of the _Silver Plague_, the inhabited Moons of Jupiter had gone mad with revelry, as if they would distill the last drop of pleasure from each passing hour that brought them closer and closer to extinction. "I wonder," Julian spoke aloud, "why decadence always hastens the tempo of pleasure!" He smiled acidly as his own voice sounded strange in his ears. Below him, the blazing tiers within the transparent enveloped, that was Atalanta, capital of Io, the great Galilean satellite, sparkled polychromatically in the night. In the utter silence, a stream of music faint and far away, like a tiny goblin orchestra reached him, as the icy wind plucked with elfin fingers at his cape. And something else reached him, too, that sent the blood racing through his veins as his hypersensitive awareness of danger, translated the sound of stifled breathing behind him into a signal for action. He whirled with a speed that was an index of Jovian training, for in the vastly lighter gravities of the Moons, his muscular coordination was breath-taking. Before him stood a Mutant in the act of crouching for a leap. He was huge, squarely built, his silver mane standing straight out as he sprang with a murderous rush. Julian stepped aside with calculated ease and his left hand moved like a piston into the Mutant's face. There was no time to seek the hidden "electro" under his arm-pit, and power-rapiers had to be checked before entering pleasure palaces. The Mutant bellowed with fury, and rammed a right deep into Julian's ribs, then brought up his left and Julian tasted the claret in his mouth. The silver-haired, silver-eyed being was obviously fighting to kill. And suddenly Julian's vast amazement changed to a cold fury that turned his blue-grey eyes to a smouldering black. He slid two sharp jabs into his enemy, then crossed his right and felt bone give under his fist. He moved in, blasting with both fists like rocket exhausts, and heard the Mutant's breath exploding from his body. The Mutant with supreme effort tossed a fist grenade at him, but Julian had caught the rhythm of the battle and swayed away with it; he made the assailant miss again, then with all his dynamic power sent his right hand crashing home.