Who—what was this stranger who seemed so interested in his whereabouts? Peter was sure that he had made no mistake. It was an unusual face, swarthy, with high cheek bones, dark eyes, a short nose with prominent nostrils. Perhaps it would not have been so firmly impressed on his memory except for the curious look of startled recognition that Peter had surprised on it at the station in New York. This had puzzled him for some moments in the train but had been speedily lost in the interest of his journey. The man had followed him to Black Rock. But why? What did he want of Peter and why should he skulk around the cabin and risk the danger of Peter's bullets? It seemed obvious that he was here for some dishonest purpose, but what dishonest purpose could have any interest in Peter? If robbery, why hadn't the man chosen the time while Peter was away in the woods? Peter grinned to himself. If the man had any private sources of information as to Peter's personal assets, he would have known that they consisted of a two-dollar watch and a small sum in money. If the dishonest purpose were murder or injury, why hadn't he attacked Peter while he was bathing, naked and quite defenseless, in the creek?

There seemed to be definite answers to all of these questions, but none to the fact of the man's presence, to the fact of his look of recognition, or to the fact of his wish to be unobserved. Was he a part of the same conspiracy which threatened McGuire? Or was this a little private conspiracy arranged for Peter alone? And if so, why? So far as Peter knew he hadn't an enemy in America, and even if he had made one, it was hardly conceivable that any one should go to such lengths to approach an issue and then deliberately avoid it.

But there seemed no doubt that something was up and that, later, more would be heard from this curious incident. It seemed equally certain that had the stranger meant to shoot Peter he could easily have done so in perfect safety to himself through the window, while Peter was fastening his cravat. Reloading his revolver and slipping it into his pocket, Peter locked the cabin carefully, and after listening to the sounds of the woods for awhile, made his way up the path to Black Rock House.

He had decided to say nothing about the incident which, so far as he could see, concerned only himself, and so when the men on guard questioned him about the shots that they had heard he told them that he had been firing at a mark. This was quite true, even if the mark had been invisible. Shad Wells was off duty until midnight so Peter went the rounds, calling the men to the guardhouse and telling them of the change in the orders. They were to wait until the company upon the portico went indoors and then, with Jesse in command, they were to take new stations in trees and clumps of bushes which Peter designated much nearer the house. The men eyed his dinner jacket with some curiosity and not a little awe, and Peter informed them that it was the old man's order and that he, Peter, was going to keep watch from inside the house, but that a blast from a whistle would fetch him out. He also warned them that it was McGuire's wish that none of the visitors should be aware of the watchmen and that therefore there should be no false alarms.

Curiously enough Peter found McGuire in a state very nearly bordering on calm. He had had a drink. He had not heard the shots Peter had fired nor apparently had any of the regular occupants of the house. The visitors had possibly disregarded them. From the pantry came a sound with which Peter was familiar, for Stryker was shaking the cocktails. And when the ladies came downstairs the two men on the portico came in and Peter was presented to the others of the party, Miss Delaplane, Mr. Gittings and Mr. Mordaunt. The daughter of the house examined Peter's clothing and then, having apparently revised her estimate of him, became almost cordial, bidding him sit next Miss Delaplane at table.

Mildred Delaplane was tall, handsome, dark and aquiline, and made a foil for Peggy's blond prettiness. Peter thought her a step above Peggy in the cultural sense, and only learned afterward that as she was not very well off, Peggy was using her as a rung in the social ladder. Mordaunt, Peter didn't fancy, but Gittings, who was jovial and bald, managed to inject some life into the party, which, despite the effect of the cocktails, seemed rather weary and listless.

McGuire sat rigidly at the head of the table, forcing smiles and glancing uneasily at doors and windows. Peter was worried too, not as to himself, but as to any possible connection that there might be between the man with the dark mustache and the affairs of Jonathan McGuire. Mildred Delaplane, who had traveled in Europe in antebellum days, found much that was interesting in Peter's fragmentary reminiscences. She knew music too, and in an unguarded moment Peter admitted that he had studied. It was difficult to lie to women, he had found.

And so, after dinner, that information having transpired, he was immediately led to the piano-stool by his hostess, who was frequently biased in her social judgments by Mildred Delaplane. Peter played Cyril Scott's "Song from the East," and then, sure of Miss Delaplane's interest, an Étude of Scriabine, an old favorite of his which seemed to express the mood of the moment.

And all the while he was aware of Jonathan McGuire, seated squarely in the middle of the sofa which commanded all the windows and doors, with one hand at his pocket, scowling and alert by turns, for, though the night had fallen slowly, it was now pitch black outside. Peter knew that McGuire was thinking he hadn't hired his superintendent as a musician to entertain his daughter's guests, but that he was powerless to interfere. Nor did he wish to excite the reprobation of his daughter by going up and locking himself in his room. Peggy, having finished her cigarette with Freddy on the portico, had come in again and was now leaning over the piano, her gaze fixed, like Mildred's, upon Peter's mobile fingers.

"You're really too wonderful a superintendent to be quite true," said Peggy when Peter had finished. "But do give us a 'rag.'"

Peter shook his head. "I'm sorry, but I can't do ragtime."

"Quit your kidding! I want to dance."

"I'm not—er—kidding," said Peter, laughing. "I can't play it at all—not at all."

Peggy gave him a look, shrugged and walked to the door.

"Fred-die-e!" she called.

Peter rose from the piano-stool and crossed to McGuire. The man's cigar was unsmoked and tiny beads of sweat stood out on his forehead.

"I don't think you need worry, sir," whispered Peter. "The men are all around the house, but if you say, I'll go out for another look around."

"No matter. I'll stick it out for a while.""You're better off here than anywhere, I should say. No one would dare——"

Here Freddy at the piano struck up "Mary" and further conversation was drowned in commotion. Mildred Delaplane was preËmpted by Mr. Gittings and Peggy came whirling alone toward Peter, arms extended, the passion for the dance outweighing other prejudices.

Peter took a turn, but four years of war had done little to improve his steps.

"I'm afraid all my dancing is in my fingers," he muttered.

Suddenly, as Freddy Mordaunt paused, Peggy stopped and lowered her arms.

"Good Lord!" she gasped. "What's the matter with Pop?"

McGuire had risen unsteadily and was peering out into the darkness through the window opposite him, his face pallid, his lips drawn into a thin line. Peggy ran to him and caught him by the arm.

"What is it, Pop? Are you sick?"

"N-no matter. Just a bit upset. If you don't mind, daughter, I think I'll be going up."

"Can I do anything?"

"No. Stay here and enjoy yourselves. Just tell Stryker, will you, Nichols, and then come up to my room."

Peggy was regarding him anxiously as he made his way to the door and intercepted Peter as he went to look for the valet.

"What is it, Mr. Nichols?" she asked. "He may be sick, but it seems to me——" she paused, and then, "Did you see his eyes as he looked out of the window?"

"Indigestion," said Peter coolly.

"You'll see after him, won't you? And if he wants me, just call over.""I'm sure he won't want you. A few home remedies——"

And Peter went through the door. Stryker had appeared mysteriously from somewhere and had already preceded his master up the stair. When Peter reached the landing, McGuire was standing alone in the dark, leaning against the wall, his gaze on the lighted bedroom which, the valet was carefully examining.

"What is it, sir?" asked Peter coolly. "You thought you saw something?"

"Yes—out there—on the side portico——"

"You must be mistaken—unless it was one of the watchmen——"

"No, no. I saw——"

"What, sir?"

"No matter. Do you think Peggy noticed?"

"Just that you didn't seem quite yourself——"

"But not that I seemed—er——"

"Alarmed? I said you weren't well."

Peter took the frightened man's arm and helped him into his room.

"I'm not, Nichols," he groaned. "I'm not myself."

"I wouldn't worry, sir. I'd say it was physically impossible for any one to approach the house without permission. But I'll go down and have another look around."

"Do, Nichols. But come back up here. I'll want to talk to you."

So Peter went down. And, evading inquiries in the hallway, made his way out through the hall and pantry. Here a surprise awaited him, for as he opened the door there was a skurry of light footsteps and in a moment he was in the pantry face to face with Beth Cameron, who seemed much dismayed at being discovered.

"What on earth are you doing here?" he asked in amazement.She glanced at his white shirt front and then laughed.

"I came to help Aunt Tillie dish up."

"You!" He didn't know why he should have been so amazed at finding her occupying a menial position in this household. She didn't seem to belong to the back stairs! And yet there she was in a plain blue gingham dress which made her seem much taller, and a large apron, her tawny hair casting agreeable shadows around her blue eyes, which he noticed seemed much darker by night than by day.

She noticed the inflection of his voice and laughed.

"Why not? I thought Aunt Tillie would need me—and besides I wanted to peek a little."

"Ah, I see. You wanted to see Miss Peggy's new frock through the keyhole?"

"Yes—and the other one. Aren't they pretty?"

"I suppose so."

"I listened, too. I couldn't help it."

"Eavesdropping!"

She nodded. "Oh, Mr. Nichols, but you do play the piano beautifully!"

"But not like an angel in Heaven," said Peter with a smile.

"Almost—if angels play. You make me forget——" she paused.

"What——?"

"That's there's anything in the world except beauty."

In the drawing-room Freddy, having found himself, had swept into a song of the cabarets, to which there was a "close harmony" chorus.

"There's that——," he muttered, jerking a thumb in the direction from which he had come.

But she shook her head. "No," she said. "That's different."

"How—different?""Wrong—false—un—unworthy——"

As she groped for and found the word he stared at her in astonishment. And in her eyes back of the joy that seemed to be always dancing in them he saw the shadows of a sober thought.

"But don't you like dance music?" he asked.

"Yes, I do, but it's only for the feet. Your music is for—for here." And with a quick graceful gesture she clasped her hands upon her breast.

"I'm glad you think so, because that's where it comes from."

At this point Peter remembered his mission, which Beth's appearance had driven from his mind.

"I'll play for you sometime," he said.

He went past her and out to the servants' dining-room. As he entered with Beth at his heels, Mrs. Bergen, the housekeeper, turned in from the open door to the kitchen garden, clinging to the jamb, her lips mumbling, as though she were continuing a conversation. But her round face, usually the color and texture of a well ripened peach, was the color of putty, and seemed suddenly to have grown old and haggard. Her eyes through her metal-rimmed spectacles seemed twice their size and stared at Peter as though they saw through him and beyond. She faltered at the door-jamb and then with an effort reached a chair, into which she sank gasping.

Beth was kneeling at her side in a moment, looking up anxiously into her startled eyes.

"Why, what is it, Aunt Tillie?" she whispered quickly. "What it is? Tell me."

The coincidence was too startling. Could the same Thing that had frightened McGuire have frightened the housekeeper too? Peter rushed past her and out of the open door. It was dark outside and for a moment he could see nothing. Then objects one by one asserted themselves, the orderly rows of vegetable plants in the garden, the wood-box by the door, the shrubbery at the end of the portico, the blue spruce tree opposite, the loom of the dark and noncommittal garage. He knew that one of his men was in the trees opposite the side porch and another around the corner of the kitchen, in the hedge, but he did not want to raise a hue and cry unless it was necessary. What was this Thing that created terror at sight? He peered this way and that, aware of an intense excitement, in one hand his revolver and in the other his police whistle. But he saw no object move, and the silence was absolute. In a moment—disappointed—he hurried back to the servants' dining-room.

Mrs. Bergen sat dazed in her chair, while Beth, who had brought her a glass of water, was making her drink of it.

"Tell me, what is it?" Beth was insisting.

"Nothing—nothing," murmured the woman.

"But there is——"

"No, dearie——"

"Are you sick?"

"I don't feel right. Maybe—the heat——"

"But your eyes look queer——"

"Do they——?" The housekeeper tried to smile.

"Yes. Like they had seen——"

A little startled as she remembered the mystery of the house, Beth cast her glance into the darkness outside the open door.

"You are—frightened!" she said.

"No, no——"

"What was it you saw, Mrs. Bergen," asked Peter gently.

He was just at her side and at the sound of his voice she half arose, but recognizing Peter she sank back in her chair.Peter repeated his question, but she shook her head.

"Won't you tell us? What was it you saw? A man——?"

Her eyes sought Beth's and a look of tenderness came into them, banishing the vision. But she lied when she answered Peter's question.

"I saw nothin', Mr. Nichols—I think I'll go up——"

She took another swallow of the water and rose. And with her strength came a greater obduracy.

"I saw nothin'——" she repeated again, as she saw that he was still looking at her. "Nothin' at all."

Peter and Beth exchanged glances and Beth, putting her hand under the housekeeper's arm, helped the woman to the back stairs.

Peter stood for a moment in the middle of the kitchen floor, his gaze on the door through which the woman had vanished. Aunt Tillie too! She had seen some one, some Thing—the same some one or Thing that McGuire had seen. But granting that their eyes had not deceived them, granting that each had seen Something, what, unless it were supernatural, could have frightened McGuire and Aunt Tillie too? Even if the old woman had been timid about staying in the house, she had made it clear to Peter that she was entirely unaware of the kind of danger that threatened her employer. Peter had believed her then. He saw no reason to disbelieve her now. She had known as little as Peter about the cause for McGuire's alarm. And here he had found her staring with the same unseeing eyes into the darkness, with the same symptoms of nervous shock as McGuire had shown. What enemy of McGuire's could frighten Aunt Tillie into prostration and seal her lips to speech? Why wouldn't she have dared to tell Peter what she had seen? What was this secret and how could she share it with McGuire when twenty-four hours ago she had been in complete ignorance of the mystery? Why wouldn't she talk? Was the vision too intimate? Or too horrible?

Peter was imaginative, for he had been steeped from boyhood in the superstitions of his people. But the war had taught him that devils had legs and carried weapons. He had seen more horrible sights than most men of his years, in daylight, at dawn, or silvered with moonlight. He thought he had exhausted the possibilities for terror. But he found himself grudgingly admitting that he was at the least a little nervous—at the most, on the verge of alarm. But he put his whistle in his mouth, drew his revolver again and went forth.

First he sought out the man in the spruce tree. It was Andy. He had seen no one but the people on the porch and in the windows. It was very dark but he took an oath that no one had approached the house from his side.

"You saw no one talking with Mrs. Bergen by the kitchen door?"

"No. I can't see th' kitchen door from here."

Peter verified. A syringa bush was just in line.

"Then you haven't moved?" asked Peter.

"No. I was afraid they'd see me."

"They've seen something——"

"You mean——?"

"I don't know. But look sharp. If anything comes out this way, take a shot at it."

"You think there's something——"

"Yes—but don't move. And keep your eyes open!"

Peter went off to the man in the hedge behind the kitchen—Jesse Brown.

"See anything?" asked Peter.

"Nope. Nobody but the chauffeur."

"The chauffeur?"

"He went up to th' house a while back.""Oh—how long ago?"

"Twenty minutes."

"I see." And then, "You didn't see any one come away from the kitchen door?"

"No. He's thar yet, I reckon."

Peter ran out to the garage to verify this statement. By the light of a lantern the chauffeur in his rubber boots was washing the two cars.

"Have you been up to the house lately?"

"Why, no," said the man, in surprise.

"You're sure?" asked Peter excitedly.

"Sure——"

"Then come with me. There's something on."

The man dropped his sponge and followed Peter, who had run back quickly to the house.

It was now after eleven. From the drawing-room came the distracting sounds from the tortured piano, but there was no one on the portico. So Peter, with Jesse, Andy and the chauffeur made a careful round of the house, examining every bush, every tree, within a circle of a hundred yards, exhausting every possibility for concealment. When they reached the kitchen door again, Peter rubbed his head and gave it up. A screech owl somewhere off in the woods jeered at him. All the men, except Jesse, were plainly skeptical. But he sent them back to their posts and, still pondering the situation, went into the house.

It was extraordinary how the visitor, whoever he was, could have gotten away without having been observed, for though the night was black the eyes of the men outside were accustomed to it and the lights from the windows sent a glimmer into the obscurity. Of one thing Peter was now certain, that the prowler was no ghost or banshee, but a man, and that he had gone as mysteriously as he had come.

Peter knew that his employer would be anxious until he returned to him, but he hadn't quite decided to tell McGuire of the housekeeper's share in the adventure. He had a desire to verify his belief that Mrs. Bergen was frightened by the visitor for a reason of her own which had nothing to do with Jonathan McGuire. Any woman alarmed by a possible burglar or other miscreant would have come running and crying for help. Mrs. Bergen had been doggedly silent, as though, rather than utter her thoughts, she would have bitten out her tongue. It was curious. She had seemed to be talking as though to herself at the door, and then, at the sound of footsteps in the kitchen behind her, had turned and fallen limp in the nearest chair. The look in her face, as in McGuire's, was that of terror, but there was something of bewilderment in both of them too, like that of a solitary sniper in the first shock of a shrapnel wound, a look of anguish that seemed to have no outlet, save in speech, which was denied.

To tell McGuire what had happened in the kitchen meant to alarm him further. Peter decided for the present to keep the matter from him, giving the housekeeper the opportunity of telling the truth on the morrow if she wished.

He crossed the kitchen and servants' dining-room and just at the foot of the back stairs met Mrs. Bergen and Beth coming down. So he retraced his steps into the kitchen, curious as to the meaning of her reappearance.

At least she had recovered the use of her tongue.

"I couldn't go to bed, just yet, Mr. Nichols," she said in reply to Peter's question. "I just couldn't."

Peter gazed at her steadily. This woman held a clew to the mystery. She glanced at him uncertainly but she had recovered her self-possession, and her replies to his questions, if anything, were more obstinate than before.

"I saw nothin', Mr. Nichols—nothin'. I was just a bit upset. I'm all right now. An' I want Beth to go home. That's why I came down."

"But, Aunt Tillie, if you're not well, I'm going to stay——"

"No. Ye can't stay here. I want ye to go." And then, turning excitedly to Peter, "Can't ye let somebody see her home, Mr. Nichols?"

"Of course," said Peter. "But I don't think she's in any danger."

"No, but she can't stay here. She just can't."

Beth put her arm around the old woman's shoulder.

"I'm not afraid."

Aunt Tillie was already untying Beth's apron.

"I know ye're not, dearie. But ye can't stay here. I don't want ye to. I don't want ye to."

"But if you're afraid of something——"

"Who said I was afraid?" she asked, glaring at Peter defiantly. "I'm not. I just had a spell—all this excitement an' extra work—an' everything."

She lied. Peter knew it, but he saw no object to be gained in keeping Beth in Black Rock House, so he went out cautiously and brought the chauffeur, to whom he entrusted the safety of the girl. He would have felt more comfortable if he could have escorted her himself, but he knew that his duty was at the house and that whoever the mysterious person was it was not Beth that he wanted.

But what was Mrs. Bergen's reason for wishing to get rid of her?

As Beth went out of the door he whispered in her ear, "Say nothing of this—to any one."

She nodded gravely and followed the man who had preceded her.

When the door closed behind Beth and the chauffeur, Peter turned quickly and faced the housekeeper.

"Now," he said severely, "tell me the truth."She stared at him with a falling jaw in a moment of alarm—then closed her lips firmly. And, as she refused to reply,

"Do you want me to tell Mr. McGuire that you were talking to a stranger at the kitchen door?"

She trembled and sinking in a chair buried her face in her hands.

"I don't want to be unkind, Mrs. Bergen, but there's something here that needs explaining. Who was the man you talked to outside the door?"

"I—I can't tell ye," she muttered.

"You must. It's better. I'm your friend and Beth's——"

The woman raised her haggard face to his.

"Beth's friend! Are ye? Then ask me no more."

"But I've got to know. I'm here to protect Mr. McGuire, but I'd like to protect you too. Who is this stranger?"

The woman lowered her head and then shook it violently. "No, no. I'll not tell."

He frowned down at her head.

"Did you know that to-night McGuire saw the stranger—the man that you saw—and that he's even more frightened than you?"

The woman raised her head, gazed at him helplessly, then lowered it again, but she did not speak. The kitchen was silent, but an obbligato to this drama, like the bray of the ass in the overture to "Midsummer Night's Dream," came from the drawing-room, where Freddy Mordaunt was now singing a sentimental ballad.

"I'm sorry, Mrs. Bergen, but if Mr. McGuire is in danger to-night, I've got to know it."

"To-night!" she gasped, as though clutching at a straw. "Not to-night. Nothin'll happen to-night. I'm sure of that, Mr. Nichols.""How do you know?"

She threw out her arms in a wide gesture of desperation. "For the love o' God, go 'way an' leave me in peace. Don't ye see I ain't fit to talk to anybody?" She gasped with a choking throat. "He ain't comin' back again—not to-night. I'll swear it on th' Bible, if ye want me to."

Their glances met, hers weary and pleading, and he believed her.

"All right, Mrs. Bergen," he said soothingly. "I'll take your word for it, but you'll admit the whole thing is very strange—very startling."

"Yes—strange. God knows it is. But I—I can't tell ye anything."

"But what shall I say to Mr. McGuire—upstairs. I've got to go up—now."

"Say to him——?" she gasped helplessly, all her terrors renewed. "Ye can't tell him I was talkin' to anybody." And then more wildly, "Ye mustn't. I wasn't. I was talkin' to myself—that's the God's truth, I was—when ye come in. It was so strange—an' all. Don't tell him, Mr. Nichols," she pleaded at last, with a terrible earnestness, and clutching at his hand. "For my sake, for Beth's——"

"What has Beth to do with it?"

"More'n ye think. Oh, God——" she broke off. "What am I sayin'——? Beth don't know. She mustn't. He don't know either——"

"Who? McGuire?"

"No—no. Don't ask any more questions, Mr. Nichols," she sobbed. "I can't speak. Don't ye see I can't?"

So Peter gave up the inquisition. He had never liked to see a woman cry.

"Oh, all right," he said more cheerfully, "you'd better be getting to bed. Perhaps daylight will clear things up."

"And ye won't tell McGuire?" she pleaded.

"I can't promise anything. But I won't if I'm not compelled to."

She gazed at him uncertainly, her weary eyes wavering, but she seemed to take some courage from his attitude.

"God bless ye, sir."

"Good-night, Mrs. Bergen."

And then, avoiding the drawing-room, Peter made his way up the stairs with a great deal of mental uncertainty to the other room of terror.