The very time when Harry Vincent lay helpless behind the wheel of the abandoned touring car, Bruce Duncan was comfortably seated in the upstairs room of his dead uncle's home. Once more he was pondering over the odd adventure that he had experienced within these walls.

Patience was not one of Bruce Duncan's virtues. He realized this as he sat in the armchair, staring at the fireplace.

Three weeks had elapsed since the mysterious visitor of the night had entered his home. During that time he had failed utterly in his attempts to discover who the visitor might be.

Nothing had disturbed him since; but he did not expect that. The thief had obtained what he had sought.

Why should he be molested further?

Three weeks — to be exact, three weeks and one night. Twenty-two days without action. It was Wednesday now; the hiding place in the hearth had been opened on a Tuesday night.

Duncan was sure of but two facts — first, that the actual thief had been an ape-faced creature that had seemed inhuman; second, that some one had been outside the window, directing the actions of the strange being.

The door opened, and Abdul, his Hindu servant, entered.

"Eleven o'clock, sahib," said the servant. "Do you need me longer?"

"Better wait up until midnight, Abdul," suggested Duncan. "By the way, what day was it that you mailed that last letter I gave you?"

"Sunday, sahib."

Duncan went to the desk and brought out some papers. He studied them thoughtfully while the Hindu moved quietly about the room.

The letters had been Duncan's only hope for a clue to the mystery which perplexed him. Among his uncle's documents he had found a list of four names which Tremaine had identified as persons with whom Harvey Duncan had conducted considerable correspondence.

Artful questioning had satisfied Bruce Duncan that the lawyer knew nothing about his uncle's connection with a prominent Russian. But it was possible that one of these four men might be able to supply some information.

So he had written them and had received three replies to his carefully worded notes. The letters that had come in indicated that the men knew nothing — unless they had deliberately sought to conceal facts. Bruce intended to investigate that later.

In the meantime he had sent a second letter to the man who had not replied. It was an urgent letter, asking for an immediate response and suggesting a visit. This was the letter that Abdul had mailed on Sunday night.

Bruce put the memoranda back in the desk and returned to his chair. At that moment the doorbell rang.

Abdul went to answer it.

The Hindu returned a few minutes later.

"Man to see you, sahib."

"What's his name, Abdul?"

"Mr. Isaac Coffran."

Duncan fairly leaped from his chair.

"Bring him in, Abdul," he exclaimed.

The visitor was the man to whom the last letter had been addressed!

The Hindu ushered an elderly gentleman into the room. The newcomer was of slight build and stoop-shouldered. He used a cane as he walked, and he turned his head upward to stare at Duncan with sharp, blue eyes that were both friendly and inquisitive.

He accepted Bruce Duncan's handshake and sat in the armchair facing the fireplace, while the young man took a position close beside him.

A strange old fellow, thought Duncan. Older than his uncle, yet alert despite his age. It was impossible to determine the exact age of Isaac Coffran. The man's face was clean-shaven, and his cheeks were smooth and tight.

"I received your letter," announced the old man in a wheezy yet amiable voice. "It seemed important, so I came to see you. It is not often that I leave my house."

He laughed; then he added: "This is the first time I have been outside for several months."

"I'm sorry," observed Duncan apologetically. "I could have come to see you."

"No, no," replied the old man. "It was only a few hours from New York. The night is mild, and the trip has done me good. A friend brought me. He is outside in his automobile."

"Would you like to stay all night?" offered Duncan.

"No, no. I am used to late hours. A habit that I have had ever since I was young like you. I can stay only a little while. Why was it that you wished to see me?"

Duncan stared speculatively across the room. He felt that he must be tactful; at the same time, old Isaac Coffran was so affable that it seemed good policy to confide in him. Duncan was anxious to learn all that he could, and although he did not intend to divulge his uncle's secret, he felt that he might be safe in giving an inkling of it.

"You knew my uncle well?" he questioned.

"Very well," affirmed the old man. "He and I knew each other for years. We had business dealings long ago — before I retired. He used to come to see me occasionally, and he wrote me frequently."

"Did you see him before he died?"

The old man shook his head.

"No," he said, "I did not. I sent my regards to him when I learned that he was ill, but I had no idea that his condition was serious. I was greatly saddened by his death. He was considerably younger than myself."

"Did my uncle have any enemies?" questioned Duncan.

Isaac Coffran smiled.

"We are all likely to have enemies" he said. "Your uncle was an active man. He was in many parts of the world. He made many friends, and I suppose he made enemies, also. Why do you ask?"

"Because" — Duncan hesitated a moment — "because I am sure that my uncle had apprehensions of some sort."

"Did he ever mention them to you?"

"No, because I did not arrive here until after he had died."

"That's right. My memory is not so good as it used to be. I recall that you were not here. I received a letter after your Uncle Harvey died that stated you came too late. I believe the letter was from your uncle's old servant. What was the man's name?"

"Hopkins."

"That's right. I received a letter from Hopkins, Ah! That's the man you should see. Hopkins. He was with your uncle for a long while."

"Hopkins is dead."

"You don't mean it!" There was a tone of real sorrow in Isaac Coffran's voice. "Poor Hopkins! Faithful servant he was. Died so soon, too!"

"That adds to my belief that my uncle had enemies."

* * *

The old man leaned over and tapped Bruce Duncan on the shoulder.

"Your imagination is at work, my boy," he said. "I don't think that your suspicions are correct. So far as I know, your uncle had nothing to conceal from any one. There is no cause for alarm."

The friendly tone was comforting.

"I wish I could agree with you, Mr. Coffran," said Duncan. "Unfortunately, I cannot. I am sure that my uncle possessed an important secret which he told to no one."

"Imagination, my boy."

"It's not imagination. It is reality. Because my uncle took care that I should learn that secret, even though I did not arrive in time to hear it from his own lips. I have read a message, written by my uncle. It told me everything—"

The old man held up a hand in warning.

"I believe you, my boy. But you must not say another word. Your uncle was a friend of mine; if he had wished that I should know his secret, he would have told it to me. Keep his secret carefully, whatever it may be."

Bruce Duncan smiled.

"I intend to do so," he said. "But there are certain facts which I can state to you. First of all, I did not read his message until one month after his death. It concerned certain documents that were hidden here in the house.

"The night before I read the message, a thief entered this room and stole the very articles that were mentioned in my uncle's message. I saw the thief at work; being ignorant of the facts at the time, I did not act."

Duncan went to the fireplace and pushed the secret spring. The stone on the hearth sprang open before the astonished gaze of Isaac Coffran. Duncan studied the old man as the latter leaned forward in his chair, his mouth gaping.

"Incredible!" exclaimed Isaac Coffran. "Incredible!"

"It is my duty," explained Duncan, "to recover the stolen articles. Inasmuch as the hiding place is known to some person besides ourselves and as it is now empty, I betray no confidence in showing it to you."

"You saw the thief, you say?"

"Yes."

"Could you recognize him?"

"I could. That is why I want to know if my uncle had enemies. The man who robbed that hiding place was scarcely a human being. He was an ape-faced monstrosity; a hideous creature who entered my window while I was half asleep. I thought that I was dreaming, until after the creature had gone."

"You have no clue whatever as to the identity of this — of this person?"

The old man's tone was almost plaintive. Duncan could recognize his concern. He felt that if he encouraged Isaac Coffran, he might stir the old man's memory.

"I have clues, now," Duncan said wisely. "I believe that I am on the trail of the thief. I have assembled facts that should enable me to find him. Remember that I have my uncle's secret. If I can gain some knowledge of his past activities, I can surely find the links that are now missing in the chain of circumstances. That is why I have appealed to you."

* * *

The old man seemed thoughtful. "Perhaps I can help you," he said slowly. "My memory is poor — very, very poor. But if this concerns your uncle's past, as it appears to do, you might be able to trace some clue if you had access to letters which your uncle had written. Am I right?"

"Exactly right."

"I have many letters from your uncle. I have forgotten the contents of most of them — probably of all of them. But I have kept them in a box at my house. Would you like to see them?"

"I should indeed."

"It will be difficult for me to bring them here. Perhaps—"

"I can come to your house in New York."

"As soon as you wish."

"To-morrow night?"

"That will be excellent."

The old man arose. Duncan summoned Abdul. The Hindu brought Isaac Coffran's coat.

"You will find my house rather strange," said Isaac Coffran as they stood at the front door. "It is an old house, in a very poor neighborhood. The locality was a good one years ago. But times have changed. I am so used to the old place that I cannot bear to leave it."

They stepped on the porch, and the old man went down the steps to a waiting automobile.

"I will be at your house to-morrow night at eight," called Duncan in parting.

"I shall expect you," came Isaac Coffran's reply.

The headlights of the car were turned on and lighted up the driveway. Strange shadows appeared in the glare — long shadows of trees, short shadows of bushes, grotesque, shapeless shadows. The car rolled away.

Duncan and Abdul went in the front door. The small porch light was still on, and another shadow appeared beneath its illumination. This shadow moved across the porch and became motionless. It was a long, thin shadow which terminated in a huge, distorted profile. The light was turned off by the Hindu servant; the shadow was blotted into nothingness, and two spots, bright as burning coals, faded into the night.

Neither of the men in the house had seen the shadow. Bruce Duncan was already on his way upstairs when it appeared upon the porch. Abdul, when he turned off the light, was too occupied to think of looking through the small window beside the front door.

For the Hindu servant was concerned with something that he held in his hand — a scrap of paper which had fallen from the pocket of Isaac Coffran's coat.

Beneath the hall light, Abdul studied the piece of paper and slowly perused the scrawled words that appeared upon it, repeating them to himself as a man who found it difficult to read:

"Find out what Duncan knows. Investigate personally. Prevent all interference. Plans are working perfectly."

Abdul read the message several times. Then a look of understanding appeared upon his dark face. He nodded, as though to himself. He folded the paper carefully and slipped it in a pocket of his jacket.