The house of Isaac Coffran was an old brick building in an obscure street on the East Side. It seemed strangely deserted to Bruce Duncan as he rang the bell alongside the massive door.

If his uncle's friend had not assured him that he should come at eight o'clock Thursday evening, Bruce would have decided that the house was unoccupied. For all the windows at the front were closed with iron shutters.

Even now he hesitated. He had rung the bell three times, yet there had been no response from within.

Still, it was exactly eight o'clock. It would be best to wait.

The door opened suddenly. Bruce started backward as he faced a huge, dull-faced man whose features were marred by a livid scar across one cheek. The fellow was considerably over six feet in height, and his frame was powerful.

"What you want?" demanded the man in a thick, guttural voice.

"Does Mr. Isaac Coffran live here?"

"Yes. What name?"

"Duncan. Mr. Bruce Duncan."

The huge man removed his bulk from the doorway and motioned for Bruce to enter. He stepped into a dimly lighted hallway, and the man closed the door and bolted it.

"Wait here," he said, indicating a chair.

The big attendant went up the stairs at the end of the hall. Duncan waited several minutes. Then he heard Isaac Coffran calling him from the head of the steps.

"Come up, my boy," were the old man's words.

Isaac Coffran seemed greatly pleased as he shook hands with Bruce Duncan in the upper hallway. He ushered his visitor into a comfortable sitting room at the back of the house.

"Well, boy," said the old man, smiling and rubbing his hands with satisfaction, "I have your uncle's letters all waiting for you."

"Have you looked through them?" questioned Duncan eagerly. "Did you find anything important?"

"I have not had time to read them. I am leaving that work to you. It is your privilege; especially as the letters would not give me any clue. I am quite ignorant of what you wish to discover."

"That's true. Where are the letters?"

"In my study. I shall take you there in a few minutes. You may be a long while reading. So I have arranged everything for you to stay all night."

"That's kind of you, Mr. Coffran."

The old man looked at Bruce quizzically.

"Were you surprised at the appearance of this house?" he asked.

"Yes, I was," admitted Bruce. "I would have thought that it was unoccupied if you had not assured me that you would be at home."

* * *

Isaac Coffran smiled. "I am not at home except to a very few friends," he said. "I prefer to keep the house closed in this manner. I have retired from the world. This is a bad neighborhood, and it is necessary to keep the house well-barred. I can't think of leaving this old home. But it is safe here. No one can enter, and Pedro, my servant, is faithful and reliant."

"He appears to be," Bruce remarked sincerely.

"Yes, and he is ignorant. It is well that he should be. It is best never to trust important affairs to servants. By the way, your own servant — that Hindu — are you sure that he is faithful?"

"Absolutely."

"He might be connected with the theft that took place in your uncle's room."

"I thought of that, Mr. Coffran. I'm sure that Abdul knew nothing about it."

"Where is he now?"

"I left him home."

"You told him that he could reach you here, of course?"

"I told him nothing. There is no reason why he should need to communicate with me. I trust Abdul, as I said; but I felt that my visit here should be kept secret. The Hindu cannot tell any one where I have gone if he does not know where I am."

"That was a wise course, my boy."

"In fact," added Duncan, "I told Abdul that I might not be home for days — or even for weeks. If I find a clue in my uncle's letters, I may start to follow it right away. So the Hindu has instructions to look after the house and wait until I return. You know how those Orientals are. He will stay on the job perpetually until he receives further instructions."

"Very good," observed Isaac Coffran. "Being at the house, he will be available if you need him."

"I was careful coming here, too," explained Duncan. "I left my car in a garage on the West Side and came this way in a taxicab. You and your servants are the only persons who know that I am here."

A crafty smile appeared upon the withered face of Isaac Coffran. Duncan was startled as he saw the sudden change in the old man's features. But the next words of his uncle's friend were reassuring.

"You are wise, my boy. From what you have told me, your uncle must have some enemy. I thought about it as I came home last night. We must be wise when we are dealing with unknown dangers. We must meet guile with guile. Your uncle was a brave and fearless man; better than that, he was keen and perceptive. He knew how to meet those who plotted against him. You remind me of your uncle."

Bruce Duncan smiled. The old man's statement was pleasing.

"Yes," continued Isaac Coffran, "you have come to the right place. I feel that I shall be able to give you good advice — after you have read your uncle's letters. Study them well, my boy; and remember everything that seems important. Then tell me what you have found in them. I am an old man; my memory is poor. Yet I have not lost my youthful ability to think clearly and cleverly. I believe that you will agree with me before long."

"It is fortunate that I met you," agreed Duncan. "Even if nothing tangible is learned by this visit, I feel that I am getting somewhere. I want action; these three weeks of idleness have tried my nerves. I am ready for danger; in fact, I would like to encounter it."

"Spoken like your uncle!" exclaimed Isaac Coffran. "He liked adventure, and he found it. Perhaps you will find it, too. But remember one thing. Caution is as important as daring. Guard your actions well."

Bruce Duncan laughed.

"Those words sound almost as if you were foretelling the future," he said.

The old man smiled. He rose from his chair, took his cane, and motioned to Duncan.

"Come," he said. "Time may be precious. You have work to do."

* * *

Leading the way down a dark hall toward the front of the house, the old man stopped at a door. He opened the portal and revealed a small room, lighted by lobed wall lamps. The apartment was lined with shelves of books.

"Step in," he invited. "This is my study. A quiet, cozy place in which you will not be disturbed."

Duncan entered the room. He noted that it contained no windows. It was a square room, with a desk in one corner where the bookcases ended. There was another special corner; it was almost an addition to the room — a small nook that projected into the wall.

Evidently it was intended as a place for a reading corner; there was a chair there and a light in the ceiling above, which was lower than the rest of the room. But the light was not turned on.

Isaac Coffran indicated the desk. A pile of letters lay upon it, under the beam of a small desk lamp.

"Your uncle's letters," said the old man. "I have not even looked through them. I know that some of them date back as far as twenty years. They are all dated, I believe, and I have kept them in regular order from beginning to end.

"My suggestion is that you read them one by one. Do not skip any of them. There may be references that will be explained in later letters. My only recollection of your uncle's writing is that he reviewed my replies in each succeeding letter. Hence they should all be self-explanatory.

"Forget time, my boy. I shall be in the front room awake half the night. Read as long as you desire, and concentrate upon your reading. It is the only way to stimulate deep thought.

"I shall close the door of the room so that you will not be disturbed. Should you wish to speak with me push this button beside the desk. It will summon Pedro, who stays up as late as I do."

Bruce Duncan sat at the desk and opened the first letter. He recognized the firm writing of his uncle.

Isaac Coffran placed a friendly hand upon Bruce's shoulder.

"Read on, my boy. Let us hope that before you have finished you will know more than you do now."

Duncan heard the door close behind the old man. There was a slight click of the latch. In comfortable silence, the young man began to read.

Outside the study, Isaac Coffran stood quiet and alert, listening at the closed door. He raised his finger to his lips as Pedro came down the hall. The servant with the scar stood as motionless as his master.

Minutes ticked by. Finally the old man smiled. It was a wicked smile, a cunning smile. It was a smile that would have startled Bruce Duncan had he seen it. It was a smile that brought an ugly, sneering grin to the face of Pedro.

Then Isaac Coffran raised a long, thin hand and pressed a button high in the wall above the door. A panel slid noiselessly into place. It concealed the door completely. When it had closed, there was no break in the wall along the hallway. One would never have supposed that a room existed behind that spot.

The old man stepped back and scanned the place where the door had been. The smile was still on his face as he raised his hands to his forehead and bowed. The action brought another grin to the face of the silent Pedro.

It was like a little ceremony on the part of Isaac Coffran, as though he had bidden farewell to some one whom he did not expect to see again.