“Why, it isn’t daylight yet,” remonstrated Elmer, with a drowsy stare.

“No,” answered Dave, seriously. “But there is some trouble over on the aero grounds, and we may be interested.”

“Say,” cried Hiram, fully aroused at the announcement, “you don’t mean trouble for the Comet?”

“I don’t know,” replied Dave. “There was an explosion. The man in the next room heard it, too. He called up the hotel clerk, and he told him that a hangar and its machine had been blown to pieces. Take everything with you, fellows,” advised the young airman. “We won’t come back here, even if this affair doesn’t affect us.”

“Do you think it does?” inquired Elmer anxiously. “How could there be an explosion of an airship? Yes, I’m ready.”

The boys hurried down the stairs. Dave, in the lead, found two men who had machines on the aero grounds. They, too, had been aroused and were questioning the clerk.

“All I got over the ’phone from the office on the grounds was what I told you,” the clerk was saying—“building and machine blown to pieces.”

“Let’s hurry,” said Hiram anxiously, as they reached the street. The two men from the hotel ran along with them. They overtook others, aroused by the explosion, and discussing it and trying to figure out what it might mean.

The guard at the gate of the grounds knew no more than what the boys had already learned. He said, however, that several from the office building had gone to the scene of the trouble. Half way across the field, a hangar man running to the office building with information, met them.

“What’s the trouble?” inquired one of the hurrying group.