Coolly, though every nerve and muscle in his body were on the alert, the Phantom took a case from his pocket and lighted a cigarette. He stood face to face with a peril of a tangible and definite kind. The protecting beard was dependable only so long as he did not attract the attention of the police and invite a closer scrutiny. It would not for long deceive an officer whose training had made him habitually suspicious of appearances and who had been drilled in the art of seeing through disguises.

Voices came from the outer room, Mrs. Trippe’s surly tones clashing with the gruff accents of Officer Pinto. The Phantom felt a tingle of suspense. It was the kind of situation he would have thoroughly enjoyed but for the fact that in this instance he could not jeopardize his liberty without also endangering his purpose.

Footsteps approached, and presently a stocky figure, with the housekeeper hovering behind, stood framed in the doorway. The Phantom, smiling serenely, felt instant relief the moment he glanced at the heavy and somewhat reddish features, with the unimpressive jaw and the stolid look in the eyes. Pinto might be a faithful plodder and a dangerous adversary in a physical encounter, but it was plain that he possessed only ordinary intelligence.

“Well, who’re you?” bluntly demanded the officer.

It was the housekeeper who answered. “He says he is Mr.——What did you say your name was?”

“Mr. Adair, of Boston,” replied the Phantom with an air of superb tranquillity, adding the explanation he had already invented for Mrs. Trippe’s benefit. “Hope I’m not intruding,” he concluded.

Pinto stepped inside, his eyes fixed on the Phantom’s face in a hard stare. Then, by slow degrees, the churlish expression left his features and a slightly contemptuous grin took its place.

“You’re welcome,” he declared. “Go as far as you like. I s’pose you’re trying to dope out how the Phantom got out of the room. Well, believe me, you’ll have to do some tall thinking.”

The Phantom chuckled affably. Evidently Pinto had classified him as one of the harmless cranks who flock in the wake of the police whenever a mysterious crime has taken place.

“I was just discussing the problem with Mrs. Trippe,” he announced easily. “It’s a fascinating riddle. I infer it has gripped you, too, since you come here in civilian clothes while not on duty.”

“Well, I’ve been kidding myself along, thinking maybe I would find the solution.” Pinto’s face bore a sheepish look. “There’s got to be a solution somewhere, you know, and——”

“And it would be a feather in your cap if you were the one who found it first,” put in the Phantom genially. “Perhaps it would mean promotion, too—who knows? But has it occurred to you that the murderer’s exit is no more mysterious than his entrance? If he accomplished a miracle getting out, he also accomplished a miracle getting in.”

“The Phantom’s strong for the miracle stuff, all right. But it’s possible Gage himself let the murderer in. Maybe he expected somebody to call. Anyhow, we know the villain got in somehow. What I’d like to know is how he got out.”

The Phantom’s eyes had been on the floor, near the point where, according to the newspaper articles he had read, Gage’s body must have been found. Of a sudden he looked up, and the gaze he surprised in Pinto’s slyly peering eyes sent a tingle of apprehension through his body. He wondered whether the patrolman was as obtuse as he seemed.

“I understand,” he said without a tremor in his voice, “that you found the room dark upon breaking in. Couldn’t the murderer have slipped out while you were looking for the light switch?”

“Huh!” The contemptuous snort came from Mrs. Trippe, who, with arms crossed over her chest, stood in the rear of the room. “How could he, I’d like to know, with me standing right outside the door and a crowd of rubbernecks at the main entrance?”

The Phantom seemed to ponder. The theory he had just suggested did not seem at all plausible, and his only purpose in mentioning it had been to turn Pinto’s thoughts in a new direction.

“I’d swear the rascal wasn’t in the room when I broke in,” declared the patrolman with emphasis.

“And he couldn’t have got out before,” remarked the Phantom, with a grin. At the same moment he felt Mrs. Trippe’s eyes on his face. She was gazing at him as if his last remark had made a profound impression upon her. He sensed a new and baffling quality in the situation, something that just eluded his mental grasp, and he began to wonder whether the housekeeper did not know or suspect something which she had not yet told.

“The Phantom’s a devil,” observed Pinto, again slanting a queer glance at the other man. “Nobody of flesh and bone could pull off a stunt like this. Maybe some day he’ll tell us how he did it. He’ll be roped in before long. Say,” with a forced laugh, “wouldn’t it be funny if he should get caught right here, in this room? They say a murderer always comes back to the scene of his crime.”

All the Phantom’s self-control was required to repress a start. Pinto’s remark, though uttered in bantering tones, was entirely too pointed to have been casual, and the gleam in his eyes testified that his suspicions were aroused.

“I think the Phantom’s talents have been grossly overestimated. When he is caught we shall probably find that he is quite an ordinary mortal. Don’t you think so, Mrs. Trippe?”

The woman started, then mumbled something unintelligible under her breath.

“Well, maybe,” said Pinto. “I’ve got a feeling in my elbow that says he’ll be caught before night, and then we’ll see. He may be an ordinary mortal, but I’ll be mighty interested to know how he got out of this room. Got any ideas on the subject, Mr. Adair?”

The Phantom’s frown masked the swift working of his mind. “Yes, but you will laugh when I tell you what they are. My frank opinion is that the Phantom had nothing whatever to do with this murder.”

Mrs. Trippe stared at the Phantom as if expecting an astounding revelation to fall from his lips.

Patrolman Pinto, too, seemed taken aback. A little of the color fled from his face, and for an instant his eyes held an uneasy gleam. In a moment, however, he had steadied himself, and a raucous chuckle voiced his opinion of the Phantom’s last statement.

“Say, you amateur dicks make me laugh. The Phantom had nothing to do with it, eh? Well, if he didn’t commit this murder, maybe you’ll tell us who did.”

The Phantom, quiveringly alert, strolled across the floor and back again. There was a bland smile on his lips and the amused twinkle in his eyes concealed the tension under which his mind was laboring.

“That’s asking a lot of an amateur detective, isn’t it?” he suavely inquired. “Maybe it will help you, however, to know how the situation looks to a lay-man. You say you are willing to swear that the murderer was not in the room when you broke in. It is almost equally certain, viewing the matter in the natural order of things, that he could not have left the room between the commission of the crime and your forcible entrance. Therefore——”

He broke off, feeling a violent rush of blood to the head. He had been talking against time, hoping to find a way of diverting Pinto’s suspicions from himself. Suddenly it struck him that his rambling discourse had led him straight to the solution of the mystery. The revelation flashed through his mind like a swift, blinding glare. To hide his agitation he lighted a cigarette. Through the spinning rings of smoke he saw the housekeeper’s ashen face, mouth gaping and eyes staring with fierce intensity.

“Well?” prompted Pinto. His voice was a trifle shaky.

The Phantom was himself again. “Well, as I was about to say, if the murderer was not in the room when you broke in, then the circumstances point straight to you, Mr. Pinto, as the murderer of Sylvanus Gage.”

For a time the room was utterly still. The policeman seemed torn between astonishment and a nervous fear. The housekeeper held her breath, her features twisted into a smile that rendered her expression ghastly.

“I knew it!” she cried. “I knew it all the time!”

“You must be crazy,” muttered Pinto, at last finding his voice.

“Not at all. But for the fact that you are an officer in good standing, you would have been suspected immediately. In the light of all the circumstances, it stands to reason that the man who broke through the door was the man who murdered Gage. No one else could have done it. Mrs. Trippe, do you remember how long Pinto was alone in the room after forcing his way in?”

The housekeeper seemed to search her memory. “It took him several moments to find the electric light switch,” she mumbled haltingly. “After that—well, he was in there for some time before he came out. Maybe two minutes, maybe five—I can’t be sure.”

“At any rate, long enough to drive a knife into Gage’s chest.” There was an exultant throb in the Phantom’s tones, the eagerness of the hunter who is tracking down his quarry. “Gage, we may assume, was awakened by the noise when the door crashed in, and sprang from his bed. You probably grappled in the dark. Then——”

Pinto interrupted with a harsh, strident laugh. “Some cock-and-bull story you’re handing us! If I killed Gage, then Mrs. Trippe here must have been in on the job. It was she who called me and told me to force the door.”

The Phantom waved his hand airily. “Because she had heard a mysterious noise. That noise may have been prearranged to give you a chance to knife Gage. I don’t pretend to understand all the minor details yet, but the essentials are clear as day. You must have committed the murder, for the simple reason that nobody else could have done it.”

“Yeh?” There was a vicious sneer in Pinto’s face. “Maybe you’ll tell me, then, why Gage thought the Phantom was the one who knifed him.”

“Because of the forged letter he had received the day before. Besides, Pinto, we don’t know that Gage thought anything of the kind. We have nothing but your word for it. You were the only witness to the declaration you say Gage made. A man who will commit a cowardly murder is also capable of telling a lie.”

Great bluish veins stood out on Pinto’s forehead. “You’re doing fine for an amateur dick,” he jeered. “All you’ve got to do now is to figger out a motive, and the case will be complete.”

“Motive? Ah, yes! The Duke has a habit of recruiting his men in queer places. Once he had an assistant district attorney on his staff; at another time an associate professor of philosophy with a penchant for forbidden things. Why shouldn’t he have a hard-working patrolman?”

Pinto’s figure squirmed beneath his gaze.

“Such a man would prove useful to the Duke, especially if he wanted to frame an enemy,” pursued the Phantom. “Nobody suspects a policeman. A man in uniform is beyond reproach. Even if the circumstances of a crime point straight to him as the perpetrator, it is always easier to suspect somebody else, particularly someone who has a criminal record. I guess you banked on that, Pinto.”

His tones bespoke a free and easy confidence, but he felt none of it. He believed that the murderer of Sylvanus Gage stood before him, but his only reason for thinking so was that, so far as appearances went, no one else could have committed the crime. He was poignantly aware that his theory would be laughed at and derided, and that he himself would be subjected to the hollow farce of a trial which must inevitably result in his conviction. Once in the clutches of the police, his chances of clearing himself would be extremely slender. “Well, Pinto, what about it?” His tones were clear and faintly taunting, giving no hint of the swift play of his wits. “Did you take the precaution of arranging an alibi?”

“No, I didn’t.” The policeman spoke defiantly. For an instant he fumbled about his pockets, as if searching for something. Evidently the object he wanted was not to be found about his civilian garb. “I didn’t have to fix up an alibi. Say, Mr. Adair——”

He paused for a moment and came a step closer to the Phantom.

“Say,” he went on, “while you’re telling us so much, maybe you’ll tell us how long the Gray Phantom has been wearing a beard.”

Momentarily startled by the verbal thrust, the Phantom was unprepared for the physical attack that instantly followed. He felt the sudden impact of the policeman’s ponderous body, precipitating him against the farther wall of the chamber. In a moment, with unexpected agility, the officer had seized Mrs. Trippe by the arm and hurried her from the room.

Then a door slammed and a key turned gratingly in the lock. The Gray Phantom was alone, a prisoner.