"That's queer," commented Frank.
"It sure is," agreed Jack.
"Does he do that often?"
"All the while since he's been here."
"And how long is that?"
"Three days now. He arrived the day after I came. How does he strike you?"
"Why, just as if he was looking for someone to come up behind him, and hit him with a brick," said Frank.
"That's it, exactly."
"And yet, what is he afraid of?" went on the elder Racer lad. "What's going to happen to him here, I'd like to know?"
"And I don't know. That's the mystery of it. Ever since he's been here he's acted as though he was afraid of something going to happen, or as if someone was going to attack him. I've been watching him, trying to find out what it means, but I can't."