“I’m allowed only three hundred demerits for the year, and two hundred by January will drop me,” muttered Dave, now becoming thoroughly uneasy.

For, by this time, he was certain that some unknown enemy had it “in for him.”  Darrin felt almost morally certain that some one—­and it must be a midshipman—­was at the bottom these troubles.  Yet, though he and Dan had done all they could think of to catch the enemy, neither had had the least success in this line.

“Eighty demerits more to go,” muttered Dave, “and the superintendent will recommend to the Secretary of the Navy that I be dropped for general inaptitude.  It seems a bit tough, doesn’t it, Danny boy?”

“It’s infamous!” blazed Dalzell.  “Oh, if I could only catch the slick rascal who is at the bottom of all this!”

“But both of us together don’t seem to be able to catch him,” replied Darrin dejectedly.  “Oh, well, perhaps there won’t be any more of it.  Of course, I am already deprived of all privileges.  But then, I never care to go into Annapolis, and I am never invited to officers’ quarters, anyway, so the loss of privileges doesn’t mean so very much.  It’s the big danger of losing my chance to remain here at the Naval Academy that is worrying me.”

Yet outwardly, to others, Dave Darrin was patient.  His surplus irritation he vented in extraordinary effort in the gymnasium, where he was making a remarkable record for himself.

But of course his worries were reflected in his studies and recitations.  Dave was dropping steadily.  He seemed soon destined to reach the “wooden section” in math.  This “wooden section” is the section composed of the young men who stand lowest of all in a given study.  The men of the “wooden section” are looked upon as being certain of dismissal when the semiannual examinations come along.

Now, for five days, things went along more in a better groove.  Nothing happened to Darrin, and he was beginning to hope that his very sly persecutor had ceased to annoy him for good.

On the sixth day, however, the chums returned from recitation in English.

“Nothing seems to be wrong here,” remarked Dave, with a sigh of satisfaction.

“Umf—­umf!” sniffed Dan, standing still in the middle of the room.  “Doesn’t it smell a little as though some one had been smoking in here?”

“Don’t even suggest the thing!” begged Dave turning white at the thought.

Tap-tap! sounded at the door.  In walked the white-gloved cadet assistant officer of the day.

“Mr. Darrin, you will report immediately to the officer in charge.”

“Very good, sir,” Dave answered.

This was again Lieutenant Hall’s day to be in charge.  Dave walked into that gentleman’s office, saluted, reported his presence under orders and then stood at attention.

“Mr. Darrin,” began Lieutenant Hall, “I had occasion to inspect your room.  The air was quite thick with tobacco smoke.  I felt it necessary to make a very thorough search.  In the pocket of your rain-coat I found”—­Lieutenant Hall produced from his desk a pouch of tobacco and a well-seasoned pipe—­“these.”