"This is the navigator detailed to determine air currents, sir," explained Roque to the chief figure, at whose right elbow the secret agent was stationed. The man in the cloak fixed his gaze on the expert with the notes. The latter accepted this as permission to speak, and read in precise manner the results of close observation during a recent aërial expedition of Zeppelins, escorted by armed German biplanes, in the vicinity of Dover straits. Henri's quick ear and thorough knowledge of the Teuton tongue put him in line of complete understanding of the report, and that it seemed preliminary to a proposed general raid of aircraft on territory with which he was well acquainted. Billy's only satisfaction was in watching his chum's change of expression as the news sifted through the latter's mind. He could see that there was "something doing." So intently interested was the gathering at the table in the reading, that the very existence of the youthful outsiders seemed to be forgotten. "Good; excellent!" commented the chief. "It's a game with double trumps." Roque held the affair at Cuxhaven as a choking memory. "There'll be quite a fall of hot shot, I promise you, if we get started right." This was the prediction of Captain Groat. His lieutenants from Friedrichshaven nodded their approval. In anticipation of a telling counterstroke by their air squadron, the plan makers at the table puffed up clouds of smoke from pipes and cigars, freely distributed by the happy Spitznagle when the lengthy discussion officially ended. In the added hours, when stone mugs were passing among the thirsty, night had fallen outside, and the benches were turned to the glowing fire. While Spitznagle was touching the tips of numerous candles with the tiny flame from a paper spiral, the empty mugs were being removed by an oddly dressed fellow, who shuffled around in carpet slippers like he was tormented with a thousand pangs of rheumatism. The boys had boosted themselves to good lookout points on the wide window ledges, behind the lively circle around the fire. The leather wallet and the survey notes of the expert air traveler lay separate and apart on the table, just as they had when the reading concluded. Billy was idly watching the halting action of the queer servitor, when, to the great astonishment of the watcher, the apparent cripple, with rapid hand movement, under cover of the wiping cloth he carried, deftly lifted and concealed the papers somewhere in the scarecrow garments he wore.