The silence got on the nerves of Andy and Dunk. It was very quiet in Wright Hall, but outside they could hear the calls of students, one to the other. Occasionally someone would come up on the raised courtyard of the dormitory and shout loudly for some chum. But there were no answers. Nearly all the freshmen were at an annual affair. The hall was all but deserted.

“Who do you think it will be?” asked Dunk in a whisper, after a long quiet period.

“Why, Mortimer, of course,” answered Andy. “Do you have suspicions of anybody else?”

“Well, I don’t know,” was the hesitating answer.

“Everything points to him,” went on Andy. “He’s in need of money, and has been for some time, though we didn’t know it. As soon as I heard that news about his father losing all his fortune, and the possibility that Mortimer might have to leave Yale, I said to myself that he was the most likely one to have been doing this quadrangle thieving.

“But I really hated to think it, for it seems an awful thing to have a Yale man guilty of anything like that.”

“It sure is,” agreed Dunk. “What are we going to do if we catch him?”

“Time enough to think of that after we get him,” said Andy, grimly.

“No, there isn’t,” insisted Dunk. “Look here, old man, this is a serious matter. It means a whole lot, not only to Mortimer, but to us. We don’t want to make a mistake.”

“We won’t,” said Andy. “We’ll get him right, whether it’s Mortimer, or someone else. But I can’t see how it could be anybody else. Everything points to him. It’s very plain to me.”

“You don’t quite get me,” went on Dunk, trying to get into a more comfortable position in their small hiding place. “I’ll admit that we may get the thief, and I’m willing to admit, for the sake of argument, that it may be Mortimer—in fact, I’m pretty sure, now, that it is he. But look what it’s going to mean to Yale. This thing will have to come out—it will probably get into the papers, and how will it look to have a Yale man held up as a thief. It doesn’t make any difference to say that he isn’t a representative Yale man—it’s the name of the university that’s going to suffer as much as is Mortimer.”

“That’s so—I didn’t think of that,” admitted Andy, rather ruefully. “Shall we call it off?”

“No, it’s too late to do that now. But we must consider what we ought to do once we capture the thief.”

“What do you suggest?” asked Andy, after a pause.

“I hardly know. Let’s puzzle over it a bit.” Again there fell a silence between them—a silence fraught with much meaning. They could hear revelry in other college rooms, and the call of lads on the campus. From farther off came the roar and hum of the city. It reminded Andy of the night he had first come to New Haven. How many things had happened in that time. He would soon be a sophomore now—no more a callow freshman.

“Do you know,” spoke Dunk, in a low voice, as he again changed his position, seeking ease. “I had an idea that Ikey might turn out to be the guilty one.”

“So did I,” admitted Andy. “That was after your watch was missing, and I found he had been in the room while I was out. But, for that matter, Link was in there, too. It was a sort of toss-up between the two. Poor Link, it’s been mighty unpleasant for him, to be accused wrongly. I wonder how that valuable book got in his room?”

“The quadrangle thief put it there, of course.”

“And there’s that case of Pulter’s book—found out near Yale Field,” went on Andy. “I suppose Mortimer had that, too.”

“Very likely, though it seems queer that he’d stoop so low as to take books.”

“He could pawn ’em, I suppose, same as he did the other things he took,” Andy continued.

“The way he used to borrow money from me and some of the other fellows was a caution!” exclaimed Dunk. “Seems as though he’d have enough to worry along on without stealing.”

“He spent a lot, though,” said Andy. “He was used to high living and I suppose when he found the money wasn’t coming from his father any more he had to get it the best way he could.”

“Or the worst,” commented Dunk, grimly. “I know he never paid me back all he got, and the same way with a lot of the fellows. But if he’s coming I wish he’d show up. I don’t wish him any bad luck, and I’d give a whole lot, even now, if it would prove to be someone else besides Mortimer. But I’m getting tired of waiting here.”

“So am I,” said Andy, with a yawn.

Again there was a silence, while they kept their strange vigil. Then, far down the lower corridor, there sounded footsteps.

“He—he’s coming!” whispered Andy in a tense voice.

“Yes,” assented Dunk.

But it was a false alarm. As the footsteps came nearer the waiting lads saw one of the janitors on his rounds. He did not see them, and passed on.

Andy was doing some hard thinking. The suggestion made by Dunk that the capture of the thief would be more of a black spot for Yale than the fact of the robberies taking place was bearing fruit.

“But what can we do?” Andy asked himself. “We’ve got to stop these thefts if we can, and the only way is to catch the fellow who’s doing it.”

They had been in their hiding place nearly an hour, and were getting exceedingly weary. Dunk shifted about, as did Andy, and it was on the tip of the latter’s tongue to suggest that they give up their plan for the night when they heard a distant door opened cautiously.

“Listen!” whispered Andy.

“All right,” assented his chum. “I hope it amounts to something.”

With strained ears they listened. Now they heard steps coming along the corridor. Curious, shuffling steps they were, not hard, honest heel-and-toe steps—rather those of someone treading softly, as on soles of rubber.

“It’s him all right this time!” whispered Andy in Dunk’s ear.

“I guess so—yes. Shall we follow him?”

“Yes. Take off your shoes.”

Silently they removed them, and waited. The steps were nearer now, and a long shadow was thrown athwart the place where Andy and Dunk were hiding. They could not recognize it, however.

The shadow came nearer, flickering curiously as the swaying of an electric lamp threw it in black relief on the corridor floor.

Then a figure came past the recess where the two lads were concealed. They hardly breathed, and, peering out they beheld Mortimer Gaffington stealing into Wright Hall.

It was only what they had expected to see, but, nevertheless, it gave them both a shock.

Mortimer moved on. They could see now why he could walk so silently. He had on rubbers over his shoes. The same trick used by the thief who had entered Frank’s room.

Mortimer looked all around. He stood in a listening attitude for a moment, and then, as if satisfied that the coast was clear, started up the stairs toward the corridor from which opened the room of Andy and Dunk.

The two waited until he was out of sight, and then followed, making no more noise than the thief himself. They timed their movements by his. When he advanced they went forward, and when he stopped to listen, they stopped also. It was like some game—a very grim sort of game, though.

There was only a dim light in the upper corridor, and, coming to a halt where the shadows were deepest, Andy and Dunk watched. They saw Mortimer stop before a student’s door, try it and then came the faint tinkle of a bunch of keys.

“Skeletons,” whispered Dunk.

Andy nodded in assent.

The manipulation of the lock by means of a false key seemed to come easy to Mortimer. In a moment he was inside the room. What he did there Andy and Dunk could not see, but he remained but a few minutes, and came out, softly closing the door after him.

“I wonder what he got?” whispered Dunk.

“We’ll soon know,” was Andy’s answer.

Mortimer went softly down the corridor. He did not try every door, but only went in certain rooms, and these, the two watchers noticed, were those where well-to-do students lived.

Mortimer made four or five visits, and then moved towards the apartment of Andy and Dunk.

“It’s our turn now,” whispered the latter.

Silently they turned a corner, just in time to see Mortimer enter their room.

“Now we’ve got him!” exulted Andy.

“Not yet; we’ve got to nab him,” whispered Dunk. “Oh, Andy, this is fierce! To think that we’re spying on a Yale man! To think that a Yale man should turn out to be a common thief! It makes me sick!”

“Same here,” sighed Andy. “But the only way to stop suspicion from falling on others is to get Mortimer with the goods. We’ve got to save Link, too.”

“That’s right,” assented Dunk. “He isn’t a Yale man, but he’s a heap better than the kind in there.” He nodded his head in the direction of their room, where Mortimer now was.

They had left a light burning, and could see, as its beams were cut off now and then, that the intruder was moving about in their apartment.

“Come on, let’s get him—and have it over with,” suggested Dunk.

“No, we’ve got to get the goods on him,” said Andy.

“Well, hasn’t he got plenty of stolen goods—those from the other fellows’ rooms?”

“I know. But if we went in on him now he’d bluff it off—say he came in to borrow a book—or money maybe.”

“But we could search him.”

“You can’t search a fellow for coming to borrow something,” declared Andy. “Come on, let’s go where we can look in.”

Silently they stole forward until they were opposite their door. From it they had a good view of Mortimer.

Just at that moment they saw him reach for the bills on the table and, with a quick motion, pocket them. Then the thief started toward a bureau.

“Come on!” whispered Andy, hoarsely. “We’ve got to get him now, Dunk!”

With beating hearts the two sped silently but swiftly into the room. They fairly leaped for Mortimer, who turned like a flash, glaring at them. Fear was in his startled eyes—fear and shame. Then in an instant he determined to face it out.

“We—we’ve got you!” cried Dunk, exultantly.

“Got me? I don’t know what you mean?” said Mortimer, trying to speak easily. But his voice broke—his tones were hoarse, and Andy noticed that his hands were trembling. Mortimer edged over toward the door.

“I came in to get a book,” he faltered, “but I——”

“Grab him, Dunk!” commanded Andy, and the two threw themselves upon the intruder.