McGee was engaged in exactly such mental speculation when he was brought to the realization of his own nearness to war by the plane-rocking explosion of a well-placed Archie. Then two other giant black roses bloomed directly in his path. Now he was presented with his own guessing game. Where would the next one be?
He swerved sharply left and dived toward a neighboring cloud. A cloud, while seeming from below to have both form and substance, is in reality but little different from a dense ground fog. It is enveloping, misty, eerie, and cuts off all visible contact with the world. If it covers a large air area, then the pilot may face some nice problems in correct and stable navigation, but if it is only a patch, he drives straight 174along his course, knowing that he will plunge out into the sunlight with the same suddenness with which he left it. Clouds are particularly welcome when Archie gunners begin to plaster the air with high explosive shells.
As McGee came out of this cloud, his attention was drawn to a number of black bursts some three thousand feet below, but which clustered around a lone Nieuport flying at a forty-five degree angle to the line of flight which McGee was pursuing. That Archie crew knew their business, and McGee thought they appeared uncomfortably near the Nieuport. Then, as he watched, the Nieuport did a strange thing. Instead of making a sudden change in direction or a quick dive, either of which would compel the gunner to make another quick calculation in his range, it merely rolled once, then dipped twice, and proceeded on its way. The Archie fire ceased as suddenly as it had commenced.
McGee streaked across another open patch of sky and entered another cloud. Coming out of this one he again spotted the lone Nieuport and corrected his own line to correspond with that of the lone flyer below. Now, studying it more closely, and with more time, he felt sure that it was Siddons’ plane. One thing certain, the red, white and blue cockades established it as an American manned plane, and who, save a novice, McGee reasoned, would roll and make a 175slight dip to escape Archie fire. That particular battery must have been too convulsed by laughter to continue their fire. Had that stupid pilot, whoever he was, forgotten what he had been told concerning Archie fire?
With the same surprising suddenness with which Archies always proclaim their presence, three more black puff balls inked the air directly ahead of the Nieuport. They were off the mark, but they furnished data for other guns which began filling the air. Evidently the gunners had not yet seen McGee, who was much higher and considerably behind the Nieuport, for they were concentrating on that plane.
To McGee’s surprise the Nieuport again rolled, then dipped twice, and the guns below immediately ceased firing. McGee decided it was time to seek the seclusion of a nearby cloud and while driving through it, do a little thinking.
What he had just witnessed was enough to make any experienced pilot think. Someone, flying a Nieuport, had a most novel way of treating with anti-aircraft gunners. He merely rolled over, straightened out, dipped twice, and the guns promptly left off their quarreling. No one could be stupid enough to reason that such manoeuver would discomfit the gunners, and yet in this case the effect was more efficacious than any manoeuver yet invented.
McGee smiled at the stupidity of the thought. It 176was effective only because it was a signal, prearranged and understood by the anti-aircraft gunners. The pilot of that Nieuport was in communication with the enemy, and McGee believed that man to be Siddons!
It all came to him in a flash. Who, better than Siddons, could have supplied the enemy with the information that brought them over to bomb the green squadron when they were stationed near Is-Sur-Tille? Someone supplied it, for Cowan had found in the pocket of the German flyer whom he, McGee, had brought down, an order disclosing the very fact that the raid had been planned on Intelligence reports. And where had Siddons gone that day after landing at Vitry on the slenderest excuse? The French Major said he had taken off within an hour. And the very next morning the squadron stumbled into a net spread by von Herzmann, and but for the timely and unexpected arrival of a large group of French Spads the harvest would have been great indeed. Could it be that Siddons had crossed the lines the previous afternoon, escaping Archie fire by a simple code of air signals, and disclosed the entire plan to the enemy?
McGee felt a hot wave of ungovernable anger sweep over him. He no longer had any doubts whatsoever. Two and two make four. Siddons was a traitor to his country. To his country? No, doubtless he was one of the many who had been trained for years 177against this very hour of need. On false records he had gained admission to the American Air Force, and now–