The room occupied by Merriwell and Hodge was not on that side of the building, so Frank, who was studying, had not witnessed the encounter between his roommate and Snell.
Fortunately, also, the blow had not been seen by any one but cadets, so it was not liable to come to Professor Gunn's knowledge, unless Wat told of it himself.
Bart found Frank in their room, and Merriwell looked up as the dark-haired boy entered with a quick, nervous step.
"Hello!" he cried, in surprise. "What's happened? Your face is dark as a thunder-cloud, and you look as if you could eat iron."
"Well, I feel as if I wouldn't have any trouble in chewing up a few pounds of iron," replied Bart. "By Jove! old man, I never realized till a few minutes ago how narrow was my escape from being a most contemptible scoundrel!"
"How is that?"
"I was taken for a thief!" grated Bart, his white teeth clicking. "Yes, sir, taken for a thief!"
"It must have been by somebody who does not know you very well."
"That's where you are wrong. It was by somebody who knows me far too well. That is why I feel that my escape from being a scoundrel was a narrow one."
Had he not seen that Bart was so serious and thoroughly in earnest, Frank must have smiled.
"Give us the particulars," he urged. "What did you do when you were taken for a thief?"
"Knocked the cad down!" snarled Bart, smashing his clinched right hand into the open palm of his left.
"That was very proper," assured Merriwell. "You did nicely, my son."
"But I do not feel any the less humiliated. If I had not given him reason to approach me in such a manner, he would not have ventured."
Then Bart related the particulars of his adventure with Snell.
"So, so!" muttered Frank. "That rascal is in this affair. The man in black has chosen a good tool."
"That man is determined to have your ring."
"I should say so. He has been to Professor Gunn and represented that the ring belonged to him." And then Frank took his turn to tell what he had learned from the head professor.
"Well, I never!" cried Bart, as Frank finished. "Why, the scoundrel has the cheek of a brass monkey! He is dangerous, Frank."
"I believe you."
"If I were in your place, I would swear out a warrant for his arrest, and send an officer after him."
"I may be forced to do so."
"And I advise you to keep your eye on Wat Snell."
"I will do that."
"In the meantime, let me take the ring long enough to make an enlarged drawing of those lines, so that you will have the map, if it is a map, even if you lose the ring. You know my ability to copy with pen and ink anything I see. My father wants me to become a civil engineer, and so I am taking a course to suit him; but, when I leave Fardale, I mean to go to an art school, and find out if I am not cut out for an artist."
"How can you make a drawing of the lines?"
"Why, I will place the ring under a microscope, and then it will not be difficult. You know I can be very accurate when I try."
"Yes, I know it, and I will think of your plan. I am inclined to believe it is a good one. Whether I should lose the ring or not, I'd like to have a copy of that map to study."
"I'll find time to do the job to-morrow, if Old Gunn will permit us to use the microscope again."
On the following day, however, Bart found no opportunity to make the drawing.
Frank watched for the man in black, who had said he would call on Professor Gunn again; but the mysterious man did not put in an appearance, and Merriwell waited his time.
Wat Snell was forced to endure no end of ridicule from his companions, as it was the rule at Fardale that a student who had received a blow or an insult must challenge the one who gave it. If he did not do so, he was regarded as a coward, and his life in school from that time was certain to be far from pleasant.
In his heart Snell was an arrant coward, and he knew that Hodge was really longing for a challenge. Wat felt sure that he would receive a severe drubbing at the hands of the dark-haired boy whom he had angered, and the thoughts of such punishment filled his soul with horror.
"I can't fight him—it's no use, I can't!" he told himself over and over. "He is a turn-coat, anyway! He did not pretend to be so conscientious till after he got thick with Merriwell. Oh, Merriwell is really the one who is at the bottom of all the trouble I have had in this school, and I hate him worse than I do Hodge.
"I'd like to get hold of that ring. Jupiter! seventy-five dollars is a price to pay for an old ring like that, but it's what that strange man in black offered me to secure it for him. There's something mighty mysterious about that ring. I wish I knew what the mystery is. I am going to ask the man when I see him this evening."
That night Snell escaped from the building and the grounds without obtaining leave. He was going to keep an appointment with the man in black.
CHAPTER XXXIII.
PLAYING THE SHADOW.
Snell was followed.
Frank had taken Bart's advice to keep an eye on the fellow, and something in Wat's actions had given him the impression that Snell was up to something that he did not care to have generally known.
With a great deal of skill, Frank kept watch of Snell till the latter slipped from the grounds under cover of darkness.
It was a cloudy night, with the wind moaning far out at sea, and the waves roaring sullenly along the base of Black Bluff, down the shore.
As may be imagined, it was no easy task to follow Wat without losing the fellow in the darkness or getting so close that the "shadowed" lad would discover that somebody was watching him.
Although he was not aware of it, Frank possessed a remarkable faculty for performing such a task. He moved with the silence of a creeping cat, and yet covered ground with sufficient swiftness to keep near Wat.
Something must have made Snell suspicious, for three times he stopped and peered back through the darkness, and three times Frank sunk like a ghost to the ground, escaping discovery by his swiftness in making the move.
Indeed, had it been possible for a third party to watch them, it must have seemed that Merriwell felt an intuition which told him exactly when Snell was going to look back.
Once or twice before they came to the road that led up from the cove, Frank lost sight of the boy he was following, but his keen ears served him quite as well as his eyes.
When the road up the hill was reached Frank was able to follow Wat with greater ease.
Suddenly Snell paused and whistled three times. In a moment a single sharp whistle sounded near at hand, and then Frank, crouching close to the ground, saw a black figure come toward Wat Snell.
The wind that was moaning over the sea swept up the road and caused something to flap around the shoulders of this figure like a great pair of wings.
For all of the darkness, Frank recognized this figure, and he was seized with an indefinable feeling of fear such as he had never felt before.
With an effort, Frank steadied his quivering nerves, remaining quiet to watch and listen.
The person who had appeared in answer to Snell's signal was the man in black, and he quickly pounced upon the boy, like a huge hawk upon its prey.
"The ring!" he cried, hoarsely. "Where is it?"
Wat