Against the metal bottom of the plane came the tiny ping of a rifle bullet or two, but for the most part the shots of the Janissaries on the tower went wild. The ground seemed rushing up to meet them. Throughout the vast oval, surrounded by its banked tiers of empty stone seats, little groups and pairs of men paused in their movements as if stricken, turned into stone, at the sight of this strange monster overhead. Only, from one group, a figure darted away, running along the hard-packed sand of the oval, eyes uplifted, arms waving wildly. As Frank glanced down, his eyes as if drawn by the force of that ant-like figure’s gaze, singled it out of all below. In his heart he knew it was Bob, and that, whether he had received their radioed messages or not, Bob realized friends were at hand. Then below him there was a crash, followed by another, and he knew Roy Stone had landed his gas bombs on the stone platform of the Janissaries, in the very center of the arena. Had they fallen into the sand, no such sound would have followed. He could not delay to gauge the effects of the gas bombs. He must take it for granted they had put the guards out of business, and proceed to land. Even if any Janissaries were left to shoot at them, the chance must be taken. The airplane could not hover longer without being brought into descent, or it would crash. Further, they must operate swiftly, or the gas wave would sweep over the arena and put them out of business, too. Against this contingency, Frank was guarded, but not the others. Roy Stone had one gas mask, but only one, and Frank had been provided with it, as upon him as flier depended the ultimate safety of all. For one thing he was grateful. The Athensian revolutionists, if anything, had underestimated the vast extent of the Coliseum. The arena oval alone was longer than a city block, and between the stone platform of the guards and the sides was room for three planes. Down swept the plane and Frank, even though his eyes were glued to the course, out of the tail of them saw a thin vapor mushrooming above the guard’s platform which he knew must be the released cloud of gas. Not a shot came from the platform as they swooped past. Ahead, the gladiators had run from the path of the oncoming plane to throw themselves prone at the base of the surrounding wall. All except one. He—a strange figure cumbered in heavy armor, of breastplate, and greaves on thighs and calves—was running parallel to them and waving. Evidently, too, he was shouting, but even though the motor was shut off his words could not be heard. There was no doubt, however, of his identity. He had torn off and cast aside a helmet with overhanging crest, and his yellow hair was bare and gleaming in the sun. It was Bob.