"The reason for dropping the cable is analogous to the reason for using drawbridges over navigable streams; there is only one landing-place for airplanes in this entire region and that is the level, grassy plateau northeast of Thusis Woods. It is so entirely ringed with snow-peaks that there is only one way to approach it for a landing, and that is through the canyon edging Thusis Woods. Now the wire cable blocks this canyon. An approaching airplane therefore hangs aloft and signals to the cable-guards, who lower the cable until it sags sufficiently to free the aerial passage-way between the cliffs. Then the aviator planes down, sweeps through the canyon, and alights on the plateau called Thusis's Garden. But now he must return; the cable must be lifted and stretched taut; and he must embark across the gulf in the little car which runs on grooved wheels to Les Errues.
"This is all we are likely to learn. Our retreat is cut off. Two cable-guards are in front of us; in front of them the chasm; and across the chasm lies Les Errues whither the aviator has gone and where, I do not doubt, are plenty more of his kind.
"This, and two carbons, I shall endeavour to send by pigeon. In extremity we shall destroy all our papers and identification cards and get what Huns we can, RESERVING FOR OUR OWN USES one cartridge apiece.
"(Signed) Nos. 76 AND 77."
It was raining furiously, but the heavy foliage of chestnut and walnut had kept his paper dry. Now in the storm-gloom of the woods lit up by the infernal glare of lightning he detached the long scroll of thin paper covered by microscopical writing and, taking off the rubber bands which confined one of the homing pigeons, attached the paper cylinder securely.
Then he crawled over with his bird and, lying flat alongside of Miss Erith, told her what he had discovered and what he had done about it. The roar of the rain almost obliterated his voice and he had to place his lips close to her ear.
For a long while they lay there waiting for the rain to slacken before he launched the bird. The men across the hog-back never stirred. Nobody approached from the rear. At last, behind Mount Terrible, the tall edges of the rain veil came sweeping out in ragged majesty. Vapours were ascending in its wake; a distant peak grew visible, and suddenly brightened, struck at the summit by a shaft of sunshine.
"Now!" breathed McKay. The homing pigeon, released, walked nervously out over the wet leaves on the forest floor, and, at a slight motion from the girl, rose into flight. Then, as it appeared above the trees, there came the cracking report of a shotgun, and they saw the bird collapse in mid-air and sheer downward across the hog-back. But it did not land there; the marksman had not calculated on those erratic gales from the chasm; and the dead pigeon went whirling down into the viewless gulf amid flying vapours mounting from unseen depths.
Miss Erith and McKay lay very still. The Hunnish marksman across the hog-back remained erect for a few moments like a man at the traps awaiting another bird. After awhile he coolly seated himself again under the dripping ledge.
"The swine!" said McKay calmly. He added: "Don't let them cross." And he rose and walked swiftly back toward the northern edge of the forest.