With these last words Borden, with a nervous glance across the grounds, at some persons approaching, suddenly darted away from Hiram. In a quandary of doubt and dread, the latter stood for a moment or two watching his movements. Borden walked along near the fence and disappeared behind the next hangar. Then Hiram aroused himself into action. He ran back in front of their own hangar and rolled out the Scout.
“Bruce,” he said hurriedly, “something’s up that may mean trouble for Dave. I’ve got to go after him. Do you want to go with me?”
“I should say I did!” cried his companion eagerly. “Jump in,” ordered Hiram. “Give us a lift,” he called out to a passing guard. “Thanks. Now then, to find Dave!”
The manner and words of the young pilot of the Scout convinced Bruce that something was wrong. He asked no questions, however. As they got into full flight, due south, Hiram was the first to speak.
“You’re our friend, Bruce,” he called back over his shoulder, “and I know you’re interested in anything concerning us or our business. The man who signaled me to the side of the hangar was the man who drew that picture of Wertz.”
“And he’s a friend of yours, too; isn’t he?” inquired Bruce.
“I am sure that he is,” responded Hiram. “He’s acted like one just now, if what he told me is true. He has discovered some new plot against us and has sent me to warn Dave, and tell him to get back to the grounds right away, and stay there.”
“I do hope nothing is wrong, and that you will be in time,” remarked Bruce anxiously.
Hiram drove the Scout to its best paces. He was familiar with the route Dave usually took to reach the sand dunes. There was one especial reach of the sterile stretch which Dave had, so to speak, appropriated as his own private training grounds.
“We’re nearly there,” announced Hiram finally. “I don’t see any trace of Dave or the Ariel, though.”