“In his hangar in the woods.  Where else would he go to—­”

“I have thought of that.  Shall we start out alone or take witnesses with us?”

“We will go alone.  Does Oswald anticipate—­”

“He is sure.  But he lacks strength to move.  He lies on my bed in there.  Doris and her father are with him.”

“We will not wait a minute.  How the storm holds off.  I hope it will hold off for another hour.”

Mr. Challoner made no reply.  He had spoken because he felt compelled to speak, but it had not been easy for him, nor could any trifles move him now.

The town was up by this time and, though they chose the least frequented streets, they had to suffer from some encounters.  It was a good half hour before they found themselves in the forest and in sight of the hangar.  One look that way, and Sweetwater turned to see what the effect was upon Mr. Challoner.

A murmur of dismay greeted him.  The oval of that great lid stood up against the forest background.

“He has escaped,” cried Mr. Challoner.

But Sweetwater, laying a finger on his lip, advanced and laid his ear against the door.  Then he cast a quick look aloft.  Nothing was to be seen there.  The darkness of storm in the heavens but nothing more.—­Yes! now, a flash of vivid and destructive lightning!

The two men drew back and their glances crossed.

“Let us return to the highroad,” whispered Sweetwater; “we can see nothing here.”

Mr. Challoner, trembling very much, wheeled slowly about.

“Wait,” enjoined Sweetwater.  “First let me take a look inside.”

Running to the nearest tree, he quickly climbed it, worked himself along a protruding branch and looked down into the open hangar.  It was now so dark that details escaped him, but one thing was certain.  The air-ship was not there.

Descending, he drew Mr. Challoner hastily along.  “He’s gone,” said he.  “Let us reach the high ground as quickly as we can.  I’m glad that Mr. Oswald Brotherson is not with us or—­or Miss Doris.”

But this expression of satisfaction died on his lips.  At the point where the forest road debouches into the highway, he had already caught a glimpse of their two figures.  They were waiting for news, and the brother spoke up the instant he saw Sweetwater: 

“Where is he?  You’ve not found him or you wouldn’t be coming alone.  He cannot have gone up.  He cannot manage it without an assistant.  We must seek him somewhere else; in the forest or in our house at home.  Ah!” The lightning had forked again.

“He’s not in the forest and he’s not in your home,” returned Sweetwater.  “He’s aloft; the air-ship is not in the shed.  And he can go up alone now.”  Then more slowly:  “But he cannot come down.”

They strained their eyes in a maddening search of the heavens.  But the darkness had so increased that they could be sure of nothing.  Doris sank upon her knees.