“I am going to call upon the friends of the young lady you saw last evening, Hiram,” he confided to his friend. “They live at the Hampton Flats,” and he gave Hiram the location. “If you like, after you get through with your shopping you can call there for me. Then we can go back to the park together.”

“All right,” assented Hiram, “I shan’t be busy for more than an hour.”

It was about eleven o’clock when Hiram started for the Hampton Flats. He finally turned into the street where the building was located. As he neared it, a man came hurriedly down its steps, passed down the street, and disappeared from view around the corner.

“Well, I’ll be bumped!” exclaimed Hiram, forcibly.

He came to a dead stop, irresolute as to the course he ought to pursue. Hiram had recognized the man as Vernon. He wondered how the rascal came to be in the building where his airman friend was.

“Why, he’s nagging Dave, that’s sure,” declared Hiram. “But why? It won’t do any good to run after him. I must tell Dave about it, though, and—there he is now.”

The young aviator appeared at just that moment. He looked up and down the street and then advanced towards Hiram as he made him out. The latter fancied he had never seen Dave look so grave and thoughtful, but our hero roused up into instant interest as Hiram said:

“I saw Vernon come out of that building just before you did.”

“What’s that!” challenged Dave. “Out of that building?”

“Yes, he did, Dave. Now what do you suppose he was doing there?”