As he spoke Ned did hear, seemingly in the air above the house, a curious, throbbing, pulsating sound.
"That's so! It is an airship motor!" exclaimed Tom. "Come on out!"
Together they rushed from the house, but, ere they reached the yard, the sound had ceased. They looked up into the sky, but could see nothing, though the night was light from a full moon.
"I certainly heard it," said Tom.
"So did I," asserted Ned. "But where is it now?"
They advanced toward the group of work-buildings. Something showing white in the moonlight, before the hangar, caught Ned's eyes.
"Look!" he exclaimed. "There's an airship, Tom!"
The two rushed over to the level landing place before the big shed. And there, as if she had just been run out for a flight, was the Eagle. She had come back in the night, as mysteriously as she had been taken away.
