"You are welcome, children of the Fatherland," he said, extending his hand, and fixing the two strangers with his piercing eyes, after this brief salutation.
"I hope we are not late," began von Spitzer, when the first salutation was over and he had introduced his companions.
"The sun is amongst the pines and the shadows of the Schwarzwald deepen," replied the professor, speaking in the language of the forest. "It was the time arranged, but"--and here he paused for a second--"there is no time for delay," and an uneasy look spread over his face.
"You don't mean that----" began the chief, but the genius forestalled him by adding:--
"Yes, strangers have crossed the clearing to-day. For the first time since I came here, I heard strange voices amongst the trees."
"But they found nothing?"
"Nothing!" ejaculated the professor.
"Good! Then my friends may view the aeroplane," said Spitzer.
"Certainly; let them follow me," and through an opening barely fifteen feet wide, the professor led the way to a combined hangar and workshop, carefully camouflaged and hidden away amongst the trees.
The next instant the two young airmen received the greatest surprise of their lives.