“Wonder what that was?” he mused. He glanced towards the windows, but there was no glare of fire. Perfect stillness reigned outside. About to leave the solution of the question until daybreak, our hero listened intently as he heard someone in the next room spring from bed, cross the room hurriedly and apparently pick up a telephone receiver.

“Hello. This the hotel office?” fell upon Dave’s hearing. “All right. Say, what was that just went off? Wait a minute? All right.”

There was a brief lapse of silence. Then the bell in the next apartment rang out sharply. A message seemed to come over the wire, the young airman could catch its crackling echoes.

“What’s that!” exclaimed the man at the ’phone. “Explosion at the aero grounds? Is that so? Hangar and machine blown to pieces! What was it? Oh, dynamite! Well! well!”

With a start and a thrill the young aviator sprang out of bed.

CHAPTER XI

IN PERIL

“Wake up, Hiram,” shouted our hero, seizing the arm of his sleeping assistant, who, rolling against Elmer, jogged him into wakefulness also.

“Ah, what did you say?” droned Hiram. “I was just dreaming that we were on the last home stretch with the Comet and——”

“Hurry up and dress, fellows,” ordered the young airman, rapidly.