We had no idea where the aero was either; but our orders were to attack its usual housing place. The pilot heard me. He said: "Approximately approaching Staten. We have little information of the Turber city. But his aero is kept some two or three miles farther ahead." Our beam had an effective range of about fifteen hundred feet. From this present altitude we would have to direct it almost vertically downward. * * * * * Lea murmured something. We followed her gesture ahead through the observation pane into the darkness of the sky. Our pilot saw it at the same instant--a black shape looming--a Turber patrol ship rushing at us! With all my air experience, my senses reeled as we dropped. I gripped my bench. We made a forward loop--nose down. I heard the rush of air as the Turber ship almost brushed us. We righted. The pilot muttered an oath. Somebody said: "Where did it go?" There was a flurry in the cabin. We could see nothing in the darkness. We flew onward. Then we made out the Turber ship, not following us, but flying north. As I turned to gaze behind us, to the north on the roof-top fighting was beginning. Torchlight gleamed--waving, moving lights there. We caught some close details on our mirrors. Our troops had come up and were assailing the Turber patrol lines. The Turberites were falling back; but beneath us, in a moment, lines of re-enforcements appeared. There were tracks here on the Turber-owned roof. We saw spots of illumination where cars were loading with fighters to be rushed north. Our image-finders showed the Turber ship. It had been rushing north--like ourselves, without lights--to meet this roof attack. A rain of missiles dropped from it. Our commander said suddenly: "Now, Tremont! Start here--ten degrees off the vertical, to the left about another ten. Hold the course as you have it, Pierson." Our orders to flash the beam! Alan and I set the range-dials. Lea with nimble fingers made the last adjustments, wound the firing tensions, and then crouched on the floor by the battery to handle the gauges of its current-flow. The projector-face swung downward through an opened aperture in the window-shield. I focused it at the agreed-upon spreading of the beam. From our instrument table some one sang out: "Eleven hundred feet altitude here, Williams. Roof ahead averages nine to eleven hundred under us--" I made the adjustments; the beam would strike with a circle of light about a hundred feet in diameter. Alan's voice: "All ready, Ed?" "Yes!" He added: "Lea?" In the dimness of our cabin interior I saw her white arm go up in answer from where she crouched. She said: "Yes--ready." Alan snapped on the current. I sat back; I was limp and cold all over. There was nothing for me to do. Nothing but watch--and listen.