about. Ned, I think I've got the right clue at last."
Ned said nothing for several seconds. Then he remarked slowly:
"Well, Tom, it proves one thing; but not the other."
"What do you mean?"
"I mean that it may be perfectly true that the button came off Mr. Boylan's coat, but that doesn't prove that he wore it. You can be reasonably sure that the coat was having a ride in your Eagle, but was Boylan in the coat? That's the question."
"In the coat? Of course he was in it!" cried Tom.
"You can't be sure. Someone may have borrowed his coat to take a midnight ride in the airship."
"Mr. Boylan doesn't look to be the kind of a man who would lend his clothes," remarked Tom.
"You never can tell. Someone may have borrowed it without his knowledge. You'd better go a bit slow, Tom."
"Well, maybe I had. But it's a clue, anyhow."
Ned agreed to this.
"And all I've got to do is to find out who was
