Tam was on the left of the diamond formation, flying a thousand feet above the bombers, and for an hour and a half his eyes were glued upon the signal light of his leader. Presently their objective came into sight: a spangle of lights on the ground. You could follow the streets and the circular sweep of the big Central Platz and even distinguish the bridges across the Rhine, then of a sudden the lights blurred and became indistinct, and Tam muttered an impatient "Tchk," for the squadron was running into a cloud-bank which might be small but was more likely to be fairly extensive.

They were still able to distinguish the locality, until three spurts of red flame in the very center of the town marked the falling of the first bombs. Then all the prominent lights went out. There were hundreds of feeble flickers from the houses, but after a while these too faded and died. In their place appeared the bright, staring faces of the searchlights as they swept the clouds.

Tam saw the flash of guns, saw the red flame-flowers of the bombs burst to life and die, and straining his eyes through the mist caught the "Return" signal of his leader. He banked round and ran into a thicker pall of fog and began climbing. As he turned he saw a quick, red, angry flash appear in the clouds and something whistled past his head. The guns had got the altitude of the bombers to a nicety and Tam grinned.

By this time Blackie's lights were out of sight and Tam was alone. He looked down at his compass and the quivering needle now pointed to his right, which meant he was on the homeward track. He kept what he thought was a straight course, but the needle swung round so that it pointed toward him. He banked over again to the right and swore as he saw the needle spin round as though some invisible finger was twirling it.

Now the airplane compass is subject to fits of madness.

There are dozens of explanations as to why such things occur, but the recollection of a few of these did not materially assist the scout. The thing to do was to get clear of the clouds and take his direction by the stars. He climbed and climbed, until his aeronometer pointed to twenty thousand feet. By this time it was necessary to employ the apparatus which he possessed for sustaining himself at this altitude. It was amazing that the clouds should be so high, and he began to think that his aeronometer was out of order when he suddenly dived up into the light of a cold moon.

He looked around, seeking the pole-star, and found it on his left. So all the time he had been running eastward.

And then his engine began to miss.

Tam was a philosopher and a philosopher never expects miracles. He understood his engine as a good jockey understands his horse. He pushed the nose of his machine earthward and planed down through an interminable bank of clouds until he found a gray countryside running up to meet him. There were no houses, no lights, nothing but a wide expanse of country dotted with sparse copses.

There was sufficient light to enable him to select a landing-place, and he came down in the middle of a big pasture on the edge of a forest of gaunt trees.