"Then for the sake of your gasolene tank pretend that you do!" fiercely whispered Tom in his chum's ear. "Play up to my game! Don't you see that fellow's suspicious of us? He thinks we've been talking about him. I win, do you understand?"
"Oh, yes," answered Jack, and then, in a louder tone, intended to allay suspicion on the part of the suspect, he added: "You win all right, Tom! I'll buy the dinner. I didn't think the train would get in so soon! It's one on me all right!"
And then, laughing and talking in seeming carelessness, as though they had not a thought in the world but the friendly wager they had made, they went back to their coach.
"That was a narrow squeak," observed Tom. "He was getting suspicious all right, and in another moment might have made an indignant demand of the guard that we cease observing him. It might have made trouble for us. We're not members of the secret police, remember."
"Well," remarked Jack, "he might have made trouble for us, but I could do the same for him. I'd let fall a hint about the map of the railway he was sketching."
"You mean all right, Jack, but I don't believe your plan would work. If that fellow really is a German spy, which I doubt, he'd destroy the