Shielding his face from the steam clouds that obliterated all view of the staircase above, Alden stood watching the billowing steam clouds in silent awe. "Terrible, aren't they, Vic?" he remarked. "I've never seen those big fellows in action. They make the portable variety look like water pistols." * * * * * As the steam barrier showed no signs of abating, an uneasy gleam crept into Nelson's dark eye, and with jaw grimly set, he cocked the Winchester and turned with the intention of lodging a complaint at the next station below; but, to his utter dismay, he beheld bronze armored figures on the next platform now training their long-muzzled steam gun across the stair. Even as he sprang back, the deadly white vapor hissed forth from the second retortii, completely barring further retreat down the stair. Like an icy flood the chill of impending doom invaded Nelson's soul. This was no accidental discharge, for with the slightest change of direction in the deflection of either retortii, death would descend upon him and his companion. Swiftly speech became impossible, as the roar of the huge retortii was deafening; the two were lost in the heart of an opaque cloud which completely blotted out the copper-hued Atlantean sky. Hot blood surged into Nelson's head while he became aware of ghostly and stealthy figures advancing through the shimmering billows of vapor. Up, up, they came, like dream men, their eyes weird and unreal. Cursing the treachery of their late host, Nelson and Alden watched dozens upon dozens of hoplites come swarming up the stairs in solid, dully-gleaming ranks. Apparently intent to take them prisoners, the foremost Atlanteans made a rush, giving the American time to fire just twice. Unable to retreat, the helpless aviators stood to meet the engulfing wave of hoplites. Nelson struck out as hard as he could at those yelling, red-bearded faces, though he knew the effort was hopeless. He was dimly conscious that Alden, not far away, also fought with the vigor of despair. With a sense of savage satisfaction, the dark haired aviator felt his fist impact solidly into a yelling, sweating face; then something struck his head and, amid a miniature sunburst, his senseless form sank limply on the damp stones of the great staircase. * * * * *