Soon, though, these would be coming into sight, I knew, and the result of our daring expedition depended upon our success in passing them unobserved. If we were seen by them, a minute would suffice for the patrols to give the alarm by distance-phone, and then from all the European air-cities ahead, from Stockholm and London and Berlin and Marseilles and a hundred others, numberless patrol-cruisers would be swiftly converging upon us in answer to the alarm. And the European battle-fleet itself, we knew, in Berlin, the air-city we had come to attack, would be swift to answer also, so that never could we hope to win through if we were but for a moment detected. But still we were rushing westward through the night, my cruiser in the lead, and still as Macklin and I peered intently ahead and below, Hilliard having taken up his station beneath, we could make out nothing but the chill masses of the great vapor-layer far beneath us, and the gleaming, rushing shapes of the cruisers behind us. Then, I peered ahead and down toward the right, with body tense, and in the next moment had snapped out the green guiding light at our cruiser's stern, and had uttered a quick order into the distance-phone before me. "European Federation patrols ahead and beneath!" I warned quickly. "All cruisers reduce to quarter-speed!" Instantly in obedience to that order the triangle of rushing ships behind was slowing, each cruiser swiftly reducing speed, the great drone of their motors dying to a steady hum. Moving forward thus, as slowly and silently as possible, I pointed downward, Macklin's eyes following my pointing finger. "The patrols!" I whispered to him. "There beneath us--moving northward!" Far beneath us indeed they were, a little circle of moving lights that hung just above the great vapor-layer and that was moving steadily toward the north, from our right to our left. Some twenty or more of those white lights there were, moving smoothly along in the same ring-like formation, and though we could not see the shapes of the cruisers from which those lights gleamed up through the night, we knew that they could be only one of the enemy's westward patrols, flying in the familiar European Federation circular formation. Watching them, Macklin and I unconsciously held our breath, while from our ship and from all the ships behind there came no sound other than the low hum of the motors. Slowly beneath those motors' lessened power our cruisers were moving forward through the upper darkness, while beneath the little ring of lights were still holding toward the north. Our presence far above them was apparently unsuspected by them.