“You may laugh,” he cried, “but what I say is true. They’ll all be prisoners, or dead!”

Mortimer shrugged his shoulders, with the air of a man who declines to pursue an utterly nonsensical proposition further.

“Enough,” exclaimed Henry. “What I want to know is where you got that air-ship?”

“That’s for you to find out,” replied Mortimer.

“And I will,” retorted Henry, with growing anger. “That air-ship was stolen from one of our camps. There’s been a traitor somewhere and that traitor I propose to discover.”

“Yes?”

“Yes; if I have to drag the secret out of you by main force.”

“You certainly stand an excellent chance of doing it!” sneered Mortimer. “This much I’ll tell you, though, so that no innocent person may possibly come under suspicion: The air-ship is not stolen property. It was built by an honest man and is the property of His Majesty, the King.”

A look of mingled astonishment, incredulity and anger came into Henry’s face as Mortimer spoke. At the closing words he startled perceptibly.

“You lie!” he cried.