"A spark plug from an automobile," mused Jack. "Well, that doesn't seem to give me much of a clue."

"Gotermobe?" asked Budge.

"No, of course I haven't an automobile," replied Jack.

"Knowoas?"

"Do I know who has? Why—By Jove! I believe I see what you mean. Say, it's lucky you found this. I'll turn detective for awhile now. I wonder how this got into Grimm's room."

"Rolled under door, I guess," replied Budge, speaking more rationally as he threw away his cud of gum. "From hall, maybe."

"That's it!" exclaimed Jack. "I see it now. Thanks Budge. I hope I succeed. I'm much obliged to you."

"'Sallright!" exclaimed Budge, as he hurried away to attend to some of his duties.

When Jack got back to his room he found quite a gathering of his chums there.

"In for it on account of that Klu-Klux business?" asked Sam Chalmers.