Amid the swirling white clouds, Nelson had ghastly visions of yellow skulls, of steaming accoutrement, of limp heaps of disintegrating bodies; then silence fell, and, before he quite realized it, he, together with Alden and three hoplites who had survived the disastrous fungus grenade, were bounding along after Hero Giles' glittering figure as he led the way down one passage after another. * * * * * Louder than ever rang the fierce cry from the rear. Behind him Nelson could see dozens upon dozens of yelling pursuers, and knew that if he were to live he must run as never before. Into a succession of spacious rooms dashed the fugitives; on through deserted armories where hundreds of bronze helmets dangled in orderly rows; and across silent barrack halls. Closer and closer sounded the pursuing feet, spurring the runners to an even more headlong gait. All at once a door loomed to the right; into this darted Hero Giles and after him pounded the two Americans and three hoplites. In an instant the six men set their shoulder to the ponderous bronze door and swung it to, just as the hiss of a retortii on the other side rose above the mad, blood-hungry clamor of the momentarily baffled rebels. Gasping and sweat-bathed, the fugitives paused only an instant. "We've gained a short passage," gasped the Atlantean wrenching off his helmet and breast plate. The veins stood out in great blue cords on his forehead, for the weight of the armor could not have been inconsiderable. "Below wait our podokos." Nelson stripped off his leather coat, following the example of the hoplites, who swiftly divested themselves of such cumbersome equipment as could readily be removed. Then, while the shouts of the thwarted pursuers swelled like a demonic chorus, and while feathers of steam crept under the great door, Hero Giles spun about and, with his short yellow hair gleaming bright, led on down another series of passages. * * * * * All at once the fugitives, now reduced by exhaustion to five, found themselves on a balcony overlooking the great valley of Atlans. Before them opened an enormous staircase and down this they dashed at top speed, infinitely relieved to be once more in the open air. Running like hunted stags, the fugitives had descended but a third of the great staircase, when, from behind, came a sudden, menacing cry that warned Nelson that the pursuers had, after going a longer way around, come once more in sight. "Ah! Poseidon blast the traitorous Edmund and his varlets! See?" panted Hero Giles pointing to a huge arch from beneath which was issuing a glittering column of shouting, swift running warriors at whose head dashed a splendidly-proportioned figure that must be Hero Edmund.