This he set down on the landing, while he passed further words with the captain; and now it was Potzfeldt who asked the questions, as though he wished to learn how things were going at the front.
Between queries and guttural replies the hidden air service boys heard a series of sounds that gave them sudden light. Jack's hand pressed on Tom's arm, as though in this manner he wished to call the attention of the other to the noise.
Many times both of them had listened to similar sounds while watching some pigeon on the barn roof dare a rival to combat, or when wooing his mate. And as they could easily trace this to the covered package which Carl Potzfeldt had just brought out of the house, the meaning was obvious.
Of course there were pigeons in that cage, homing pigeons at that, like the one Tom had shot! Doubtless had that one escaped its tragic fate the message it carried would have been delivered to the owner of this lonely house, in turn to be handed over to one of the messengers from German headquarters.
And now the German captain, stooping over, took possession of the cage containing at least two of the trained birds. They would be carried to some point from which, on another night, a daring Boche airman would attempt to take them far back of the French front, to hand over to the agent who was in communication with the master spy, Carl Potzfeldt.
It was all very simple. Nevertheless it was also amazing to realize how by what might be called a freak of fate the air service boys had been enabled to discover these facts. But for the accident to the motor they would not have dreamed of making a landing short of the aviation field at Bar-le-Duc. Then, had they not caught that woeful sound of loud sobbing, the idea of looking around would never have occurred to them.
The officer was now starting back to his car, which would carry him post-haste to German headquarters, where the fresh message in a cipher code from beyond the French lines might be translated, and the valuable information it possibly contained be taken advantage of.
Presently the military chauffeur started to swing around a curve that would allow them to leave the grounds by the same gates through which they had entered. The car's course could be followed by the strong ray its one light threw ahead; and the boys were able to tell when it reached the road again.
As they expected it returned the same way it had come, probably heading for the headquarters of the Crown Prince.