At first the waiters said no. But presently one scratched his head thoughtfully and said he now remembered that somebody had passed through the dining-hall after everything was in readiness for the evening repast. It had been somebody in uniform, but who he could not remember.

“I believe that person doctored that drinking-water, or my food,” said Jack, when he heard of this.

“Do you suspect anybody?” asked the master of Putnam Hall.

At this Jack shrugged his shoulders. Yes, he could suspect several—Coulter, Paxton, Ritter, and their cronies—but what good would that do if he could not prove somebody guilty?

The next day the young major felt quite like himself again and rejoined his chums. All went for a sail on the Alice, and on the trip they talked the affair over from every possible standpoint.

“If it was a trick—and I don’t see how it could be anything else—it is the most dastardly thing I ever heard of,” declared Pepper.

“That’s true,” answered Andy, “and the fellow guilty of it ought to be run out of Putnam Hall.”

“I suspect Ritter,” said Stuffer, “for he wanted to win that contest.”

“You may be right,” answered Dale. “But it is one thing to suspect a fellow and another thing to prove the crime. I wouldn’t say anything about it until I could prove it.”

“Wonder if it is possible those fellows with the green masks and hoods had anything to do with this?” mused Andy.