All at once, as he stood leaning for a moment against a tree and looking out over the river, he heard the sound of oars in row-locks below him, and, glancing down, saw a big rowboat, rowed by two men, with a barge in tow, loaded with wood. It passed slowly on up the river, Bob’s eyes on it until it was a hundred feet away. At sight of the wood he had given a start. Usual and commonplace as such a cargo was, it recalled all of last night’s revelation to him now. He looked at the rowers and recognized Franz and the stoop-shouldered man who had met him at midnight in the clearing. At the rowboat’s stern was a little canvas shelter. Bob tried to peer beneath it, but without success. Was Elizabeth crouching there? Tensely he stood a second longer, watching. In that second he saw a French torpedo-boat bear down upon the wood-barge, and saw Franz hoist the flag that was his permit to navigate the river with his cargo.
“Fooled by that Boche!” Bob thought, anger rising again hotly in him. He turned and ran from the Embankment.
His one thought now was to follow Franz to his destination. But he had no motor-boat at his disposal, and to find one was not, like Lucy’s, his first idea. Another and a swifter means of travel occurred to him, as for two years back it had done in every predicament where there was distance to be covered. He met an army motor-car passing through the streets and, hailing the driver, asked to be taken to the Air Field.
Airplanes were few in Coblenz, but Bob got hold of one, for the use of an airplane was a thing no one in the Allied armies could refuse Bob Gordon. He gave the engine of the Curtis biplane offered him the merest glance over. He knew the flight could be but a short one. He promised the frankly curious lieutenant in charge to return the plane that night and to tell him all about it. In half an hour after he had seen Franz glide past the Embankment, and about the time that Larry sent his message to Major Harding, Bob was up in the air and flying over the Rhine.
He found glasses in the plane’s cockpit, and with them searched the river, flying at low speed about eight hundred feet above the water. It did not take him long to find the rowboat with the barge in tow. It was moving steadily on up-stream. He mounted higher and flew over the castle of Ehrenbreitstein, in case the hovering plane should arouse Franz’ suspicions. It was easy enough to keep the barge in sight on its slow progress. He floated about among the clouds until Franz and his fellow-oarsmen turned in close below the hamlet of Altheim.
Bob watched them land, draw the barge in and moor it, after which Franz’ companion began rowing on up-stream alone. But through his glasses Bob had seen a woman’s figure step from the boat on to the landing-stage and follow Franz up the hillside, almost running behind his big strides. Sinking lower, Bob saw Franz and Elizabeth turn from the hamlet road to climb the slope toward the lonely cottage, then he flew on over the hamlet to the pasture lands beyond.
Twilight was falling, and Bob’s last Archangel flight had left him with no love for night landings on unknown ground. Without more delay, he picked out a stretch of level meadow that made a high, narrow valley behind the hamlet. He flew slowly down and landed on the snow-covered grass.
Lights had begun to twinkle from the near-by houses, and dusk had turned everything violet and grey around him. He caught sight of a boy’s dim figure crossing the field, and with a shout ran over to him.
“Do you want to earn something guarding my airplane?” he asked the lad, who had stopped to stare at him. “Can I trust you to let no one come near it?”
“Ja, ja, Herr Officer,” consented the young German eagerly. “No one would dare when I tell them you are coming back.”