Starr doffed his hat and ran his fingers through his long, glossy hair. The discoloration of his nose had diminished greatly, but his face was still pale and drawn.

"That's precisely my idea," he said nervously. "I shall never feel safe until that scoundrel is behind iron bars. Unless he has a private grievance against me, I am at a loss to understand why he can't keep away from my theater. By the way, did you obtain any light on the things that were puzzling you?"

"Not much," said Culligore disgustedly, with a furtive glance at the telephone. "I searched every square inch of the place without finding what I was after."

"Yes?" Starr seemed politely curious. "I infer, then, that you had a definite object in view, that you were not just searching at random."

"Oh, no." Culligore looked about him as if not quite at ease. "I suppose we're alone?"

"Not another soul in the building. You can speak as freely as you like."

"Then I'll tell you exactly what I think. The way Mr. Shei's men have been sneaking in and out of this place is mighty suggestive. Just why they should be turning your place into a rendezvous is something I don't understand, but that's exactly what they seem to be doing. They were right on the job the night you opened your new play. They gave Virginia Darrow a shot of poison just at the psychological moment, before she could spill what she knew. Then they sneaked the body away right under our eyes, and we have not yet discovered how they managed it. Only the other day, somebody took a shot at either you or The Gray Phantom. All this looks mighty queer."

"It does," a.s.sented Starr. He took out a jewel-studded case and lighted a cigarette. His pale, uneasy eyes did not leave the detective's face for a moment. "What is your theory?"

Culligore looked musingly into s.p.a.ce. "Mr. Shei is very clever, but he is of flesh and blood, like the rest of us. There must be a simple and natural explanation for all these strange doings. I'll bet my hat that he has found a secret entrance to your place."

"Impossible," said Starr promptly. "This theater was built according to my own directions and my own architects supervised every detail of the construction."

"That may be, but I still stick to the idea of a secret entrance.

Don't you see, Mr. Starr, even if you didn't have such an entrance made when you constructed your theater, Mr. Shei's men may have drilled a hole through the wall or the floor somewhere? Nothing else explains how they have been slipping in and out of the place."

"But why?" demanded Starr, and his fingers trembled as he took the cigarette from his lips. "Why should they do such a thing?"

Culligore smiled faintly while his muddy little eyes scanned the other's face.

"I think you can make a pretty fair guess," he said dryly.

Starr's face turned a shade paler. For an instant there was a look of positive dread in his eyes, but it vanished quickly. A sad smile came to his lips.

"I see I must be frank with you," he murmured, "much as I dislike to discuss matters pertaining to my private life. Don't ask me to go into details, for there are excellent reasons why I should not do so. In plain words, I do not care to incriminate myself. I have not always been what I am to-day. There was a time, quite a number of years ago, when I led a very violent life and when the law and I were not on the best of terms. I made enemies--a number of them--and it is possible that they are pursuing me to-day. In fact I----"

He paused, and his narrowing gaze slanted to the floor. Culligore repressed a start. In the intense silence of the moment he heard a faint buzzing. Somewhere, in one of the offices on the ground floor, a telephone was ringing, and he guessed that Fairspeckle had grown impatient and was calling one of the other departments of the intercommunicating system.

"In fact," Starr went on after a moment's pause, quickly controlling his astonishment, "if I were to come face to face with Mr. Shei to-day, I strongly suspect that I would recognize in him one of my old enemies. Don't ask me to explain any further, Culligore. You will appreciate the delicacy of the matter."

"I do, and you've said enough to explain the funny doings that have been going on here. I want you to answer one question frankly. Have you any idea who Mr. Shei is?"

"Have you?" was Starr's prompt rejoinder.

Culligore chuckled. "Maybe I have and maybe I haven't. I'm pretty sure of one thing. Some people think The Gray Phantom is Mr. Shei, but they're dead wrong."

Starr's lips twitched into a knowing smile. "I agree with you, there, Culligore. Shall we go a step farther? With The Gray Phantom eliminated, the range of available suspects narrows down to one man.

Am I right?"

"I think you are on the right track, Mr. Starr."

The theatrical manager, once more quite composed, seemed to find a great deal of amus.e.m.e.nt in the speculative drift of the conversation.

"It is diverting to try to read other people's minds," he observed. "I wonder how close I can come to an accurate reading of yours. A detective's thoughts travel a devious route, but I will try to look at the situation from your point of view, taking all the circ.u.mstances into account. If you were to mention the name of the one remaining suspect, I fancy it would be W. Rufus Fairspeckle."

Culligore stared as if dumfounded at the other's astuteness, but his lips curled into the faintest grin as soon as Starr averted his gaze.

"You might as well admit that I was right," said the manager with a smile of elation. "For once a mere layman has read your mind like an open book. The next question is what has become of Fairspeckle. Do you suppose----"

He broke off short. His glance darted involuntarily to the automatic telephone on the desk. Its summons sounded clear and distinct in the tense silence. Once more a tinge of gray crept into his face. With a tightening of the lips he looked furtively at Culligore.

"Queer!" muttered the lieutenant, fingering the green cord attached to the instrument and tracing it to the sound box. "Someone is calling on the private wire. And you just told me that you and I were alone in the building."

The buzzing continued. Starr stared helplessly at the instrument, but out of the tail of an eye he was watching the expression on the detective's face. Finally, with a jerk of the shoulders, he emerged from his daze.

"I don't understand it," he murmured, "but we shall soon see what it means."

He sat down and drew the instrument to him. His face took on a look of determination, but there was also a baffling and inscrutable expression that might have puzzled the detective. But Culligore's thoughts seemed to be elsewhere. He looked as though he foresaw a critical moment and realized that quick thinking and prompt action were necessary. While Starr was speaking into the telephone, he looked quickly about the room. From his vest pocket he took a small box and removed the lid, exposing a reddish substance that looked like salve.

Rubbing a little of it onto his finger tips, he softly crossed the room and quickly smeared a thin coating of the reddish material on the doork.n.o.b.

Starr hung up the receiver just as the little box disappeared into Culligore's vest pocket.

"I don't understand it," said the manager frettingly. "Someone was speaking. It was a man's voice, but I couldn't make out what he was trying to say. It is very mysterious." He smiled faintly. "It's beginning to look as though I was mistaken and there was someone else in the building besides you and me."

"It certainly looks queer," admitted Culligore. "I searched everywhere, but we might as well go over the ground again."

Starr acquiesced readily, and Culligore saw to it that the manager preceded him out of the room. He noticed with gratification that the other's fingers closed firmly around the k.n.o.b as he opened the door, and he knew that Starr was too preoccupied to take heed of the faint smear left on his hand from contact with the greased metal. He chuckled inwardly as he followed the manager down the stairs and through the offices in front of the building. After a brief and somewhat perfunctory search, they entered the auditorium.

"Shall I switch on the lights?" whispered Starr, walking beside the detective.

"I wouldn't. If there's a prowler around the place, we don't want to warn him. My electric flash will do."

For a time they conducted the search in silence, the detective cautiously darting the electric gleam over floor and walls and into dark corners. Finally he paused before a niche in the wall and pointed to an aperture behind the marble shelf that spanned the opening.

"Do you know," he whispered, "that the other day, while I was talking with The Gray Phantom, I had a funny feeling someone was hiding back there and listening to our conversation? Who do you suppose it could have been?"

There was no response. Culligore had been peering into the recess behind the marble ledge. Now he looked up quickly, but Starr was gone--and the twitching of the detective's lips signified that the manager's sudden disappearance did not surprise him greatly. In an instant he was amazingly alert. Jerking his electric flash hither and thither, he moved quickly back and forth within the narrow s.p.a.ce where he had last seen the manager, sweeping the surrounding objects with his electric gleam and examining the surfaces of chairs, pillars, walls, and decorative articles.

Presently he brought up in front of one of the larger pillars supporting the balcony. He had previously noticed its huge dimensions, and now he gauged them again with a quickly calculating eye. It was there The Gray Phantom had stood when the mysterious shot was fired the other day, and Helen Hardwick had been leaning against the same pillar when the curious individual with the repulsive features glided past her.

The electric gleam moved swiftly over the white surface of the post with its ornate tr.i.m.m.i.n.gs of dull gold. Again, as once or twice before, he wondered whether there was any hidden significance in the fact that The Gray Phantom had stood in this identical spot at the moment the shot was fired. Was it possible that the skulking a.s.sailant had feared that The Phantom was about to make an important discovery, and was that why he had fired the shot? Culligore pondered the question while scanning every square inch of the pillar.

Suddenly the electric gleam stopped at a point near the floor, and Culligore could scarcely repress an exclamation of elation. His ruse had succeeded, for on the white surface of the post was a faint discoloration which signified that Starr's hand had recently touched that particular point. There were no other marks, and this one was only a few inches from the floor. Culligore's fingers ran quickly over the surrounding s.p.a.ce, and occasionally he pressed his thumb firmly against the wood, but without discovering anything. His hand slid downward to where the rich Persian carpet was neatly tucked around the base of the post, and suddenly his exploring fingers touched a slight k.n.o.blike projection. He pressed firmly, and he felt an exultant tingle as there came a soft, whirring response. A panel in the post, ingeniously hidden in the gold-lined grooves, was sliding back, forming an aperture.

The electric gleam showed a look of keen elation on Culligore's face.

His discovery had taken only a minute or two of valuable time, for he had moved fast since he noticed that Starr was gone. Yet, but for a happy inspiration and the resultant reddish stain on the post, he might have searched for days without finding the opening.

Now he squeezed his figure through the narrow aperture, at the same time pocketing his electric flash and drawing his automatic. His feet encountered the upper rungs of a ladder that pointed straight down. He descended rapidly, making no sound. At the bottom was a narrow pa.s.sage extending in the direction of the street, and at its farther end he saw a faint glow. He approached quickly, warned by a sixth sense that he had no time to waste.

He came to a door. It stood open a crack, and through the narrow opening he saw a strange scene. An elderly man, with a thin and haggard face and sunken eyes that stared about him in an agonized way, was lying on a cot. Starr, bending over the rec.u.mbent man, was winding pieces of rope around his feet and hands and drawing them into tight knots.

"There, Mr. Fairspeckle," he tauntingly declared when he had fastened a gag around the other man's mouth, "I don't think you will work loose a second time. Even if you should, you will find that the telephone is out of order."