As the leader saw me, his swarthy face lit for a moment with a flash of recognition, of astonishment; and then he and his fellows were leaping toward us, their hands flashing down toward the heat-pistols at their belts as the attendants around the room jerked forth their weapons also. But as they did so, our own heat-pistols flashed up and for the next instant the great room seemed full of flares of blinding light as the cartridges burst among them, sending them staggering and swaying and falling in seared heaps! I shouted to my men swift orders that sent a score of them to the great switch-panels to take the places of the attendants there; while the remainder rushed toward the great doors that opened from the tower's lowest level into the plaza outside. Swiftly they closed those doors, barred them and massed behind them, and then I was rushing toward the great dull-glass ball at the room's center. Inside that ball stood the great table-map upon its great block, while beside it were the six levers and speed-knob which controlled the speed and direction of Berlin. As I took the seat before them now, I gazed about me, and saw that the great ball's interior was in effect a great periscopic screen itself, one in which I could gaze in any direction through the other great ball above the static-tower's tip. And now, gazing into it around me there, I could see that in the outer night there stretched still the giant ring of the enemy cities, of which this Berlin was the heart, surrounding our own survivors and hammering them still with that deadly fire which would soon bring them crashing to earth. Far out over that mighty field of battle, its brilliant lights and blinding heat-flares stabbing the darkness, and its thunderous roar of guns shaking the air, I could gaze; while even at the same moment I heard, high above, Connell and Hilliard and their men engaged fiercely in holding the guards in the upper tower back. At the same instant came a sudden knocking, an alarmed rapping and then a battering and crying of voices against the great tower's door from outside; as the alarm spread from the tower's upper levels!