"Nothing on earth could save them," said Tagala emphatically. "The secret is in my exclusive possession. No other man could diagnose the malady, much less prescribe a remedy. The lives of the seven gentlemen are absolutely in my hand."

"Then there isn't the slightest chance of Mr. Shei's plans falling through?"

"Not the slightest. The seven gentlemen will pay Mr. Shei's price, and within a week we shall all be rich beyond the dreams of avarice." The gloating tones hinted that Doctor Tagala's imagination was luxuriating in enchanting visions. "By the way, when do we inoculate the young lady?"

"Better wait till evening," suggested Slade. "There will be less danger of interruption then."

Helen turned away. She feared an involuntary cry of horror would betray her if she remained longer. Steadying herself with great difficulty, she stole out of the laboratory and slipped back into her room. Her watch showed half past five, and the inoculation would probably not take place for an hour or two. In the meantime she wanted to think and if possible find a way of escape, but the fierce pounding of the blood against her temples seemed to preclude clear thinking.

Her only distinct thought was that she must flee from Azurecrest no matter what dangers and difficulties she might encounter. She felt that The Gray Phantom would gladly fling his life away in order to protect her, but in this instance his hands were tied. He could not make a single move without rendering her predicament worse, and that fact would restrain him, much as he might rebel against his enforced inaction. Mr. Shei's men would point out to him that her safety depended on an unresisting att.i.tude on his part. He could not know what she had just learned from the conversation between Slade and Tagala, that it was their intention to take her life, anyway.

Somehow, she told herself, she must manage to escape from the horrors awaiting her at Azurecrest. Even being clawed and torn by the savage dog seemed preferable to the slightest touch of Doctor Tagala's hand.

She shuddered whenever her imagination conjured up a vision of his repelling features, and a hoa.r.s.e cry rose in her throat at thought of being inoculated with the fearful malady. Miss Neville's maniacal outbursts were still ringing in her ears, and she remembered the hideous strains that had poured from the lips of the dying woman in the Thelma Theater.

The recollections filled her with sickening terror. With ghastly visions floating before her eyes, she rushed blindly from the room.

The hall was deserted, and she scurried down the stairs as if pursued by a monster. She reached the outer door without hindrance, and a flickering hope began to stir within her as she scanned the wide stretch of lawn surrounding the house. The long shadows cast by the trees gave her an additional sense of safety. Swiftly, without a backward glance, she started to run. Her hopes rose higher and higher as she plunged into the thick shadows among the trees. In a few moments now, if her flight remained unnoticed, she would have reached the fence. Somehow she would manage to scale it, or maybe she could find an opening somewhere.

She quickened her pace, but of a sudden a low, rumbling growl sent a chill through her veins. She stopped, stood crouching behind the scraggy trunk of a hemlock, and glanced wildly in all directions. With great leaps and skips, a huge, black form was rushing toward her, its teeth gleaming ominously between slavering jaws. In a few moments it would be at her throat, and then---- Once more a vision of Doctor Tagala's repulsive features filled her with dread. Again she looked about her, then raced swiftly in the direction where the shadows were thickest. Behind her the underbrush crackled beneath the paws of the savage beast. In a moment or two he would be snapping at her heels.

Again hope rose within her. A squatty shed loomed within a narrow clearing. With the strength of frenzy she sped toward it. If she could reach it before the dog could overtake her, she would be temporarily safe. A great terror urged her on with the speed of the wind. Now the dog was s.n.a.t.c.hing at the hem of her fluttering skirt, but she was already at the door. With a final exertion of strength she pushed it open and rushed in, then slammed it shut behind her. With a deep breath of relief she lurched against the wall. Suddenly she recoiled as from a blow.

"What are you doin' here?" queried a gruff voice.

She stared into the dusk around her. A few wisps of waning sunlight straggled in through a small window in the rear. Gradually, as her eyes grew accustomed to the dusk, she descried a stocky figure leaning over a shovel. It was the sour-faced individual who had opened the gate for her on her arrival at Azurecrest. Little by little, as her pupils responded to the dim light, she took in each detail of the scene. An amazed gasp slipped from her lips.

An oblong s.p.a.ce had been torn up in the center of the flooring and on each side of it were little mounds of dirt. Instinctively she stepped closer and looked down into a rectangular hollow. She had a weird sensation that she was looking into a grave, and with a shudder she glanced up into the man's face.

"What--what's that?" she asked hoa.r.s.ely, indicating the hollow.

The man guffawed. "Better not ask questions, miss. This is a nasty job, and you'd better clear out."

He looked aside just then, and she followed his glance. In a corner of the shed she saw a heap vaguely resembling a human form. Her feet seemed to drag her forward in spite of her horror, and she lifted the blanket that covered the figure. Then she stood rigid, her tightly drawn lips stifling the cry that rose in her throat. At once she recognized the features of Miss Neville, the woman whose maniacal laughter had startled her the night she arrived at Azurecrest. The face was white and rigid now, but the wraith of a ghastly smile lingered on her lips. A long, shuddering moan escaped her, and then she sank limply to the floor.

She had a weird sensation, during the hours that followed, that she was treading on the brink of oblivion. A merciful mist seemed to obscure everything. She was dimly aware of being carried from the shed and placed on a long, white table. Through the haze that engulfed her she glimpsed the repulsive features of Doctor Tagala. She felt a sting in the arm, and then a sickening substance raced through her veins.

For a time she felt as though unseen hands were wafting her body through a limitless void. Somewhere--far away, she thought--there was laughter, and she had a curious impression that it was coming from her own lips.

Dawn came, and a flood of sunlight brightened the void through which she was roaming. The strange and wild fancies that had flitted around her throughout the night seemed to melt away, and now she saw things more clearly. She was standing at a telephone, and over the wire came a voice that sounded strangely familiar. Words poured from her lips, but they seemed futile and meaningless, and then an involuntary contraction of laryngeal muscles filled the room with wild strains of laughter. It frightened her, and just then a hand jerked her away.

"That'll do," said a voice, and she thought it was Slade's. "The Gray Phantom has heard enough."

CHAPTER XVI

CHECKMATED

A ma.s.s of jagged, elongated clouds hovered like scowling specters over Azurecrest. A raw wind sighed moodily among the birches and hemlocks as The Gray Phantom reached the apex of the hill. Stopping within fifty yards of the high picket fence, he glanced toward the house that once had served him as a retreat and shelter against the activities of the police. The white tr.i.m.m.i.n.gs of doors and windows gleamed faintly in the dusk and here and there a light twinkled through the trees.

The Phantom turned away and walked a few paces toward the fence. On the trip from the city he had tried to exclude Helen from his mind, for each thought of her was maddening, and he needed a cool brain and a steady nerve if he were to accomplish his purpose. By sheer force of will he had tried to forget the hysterical laughter he had heard over the wire and which had told him with grim eloquence what had happened to her. To keep disturbing thoughts from his mind, he had outlined several plans of procedure and prepared himself for the difficult and perilous task that awaited him.

After a brief search over the rugged ground, he stopped at the side of a huge bowlder and cleared away an acc.u.mulation of dry twigs, dead branches, and rotting weeds. After the obstruction had been removed, an opening barely large enough to permit him to crawl through appeared at the base of the rock. It slanted gently into the ground, then widened into a tunnel in which he was able to walk upright. During his sojourn at Azurecrest it had often occurred to him that an emergency exit might some day prove desirable, and he had built the tunnel in consequence. He had not happened to mention the existence of the pa.s.sage when he sold the place, and he did not think it likely that the new owner had discovered it. Though he had never had occasion to use it during his occupancy, it now gave him a distinct advantage in that it enabled him to enter the house secretly and by an easy route.

Reaching the farther end of the tunnel, he fumbled along the wall until he found a spring deftly hidden in a crevice. Evidently the mechanism was still in good working order, for a door swung squeakily on unoiled hinges. He pa.s.sed inside, touched another spring, and the door swung shut. In another moment he had switched on an electric light.

The room was narrow and almost square, and there were neither windows nor visible doors. It was supplied with air through ingeniously hidden ventilators and The Phantom had fitted it up for brief occupancy.

Occasionally it had suited his mood to retire to the hidden chamber and read one of his favorite books.

Throwing off the light overcoat he had been wearing, he then examined his automatic and the little pocket case in which he carried a number of carefully selected tools that had stood him in good stead in numerous emergencies. Despite the advantages afforded him by the tunnel and the secret room, he would be surrounded by dangers at every step. He had no doubt Mr. Shei's henchmen would kill him on sight, and he could not afford to toss his life away recklessly while Helen was in danger.

He glanced at his watch. It was only a little after ten, and sounds reaching him through the ventilator shaft warned him that the occupants of the house were still about. As soon as the house had quieted down a little, he would try the first plan on his programme.

If that failed, he was holding two or three others in reserve.

For half an hour he waited, then a sliding panel opened at his touch on a spring, and he ascended a narrow spiral stairway that terminated in what appeared to be a blank wall. His hand touched a lever, and The Phantom pa.s.sed through an aperture that instantly closed behind him.

He was standing in a dark room in a seldom frequented part of the house. He advanced a few steps, then stood still, listening. Someone was laughing, and in the darkness the sounds impressed him even more forcibly than they had in the light of day. He walked on, trying desperately to exclude the agonizing accents from his ears. Hurriedly he opened a door, then as quickly drew it to again. Someone was pa.s.sing in the hall outside.

He waited till the footsteps moved away, then looked warily out. A tall figure, walking with a brisk, swinging gait, was turning into one of the rooms farther down the corridor. As soon as the door had closed behind him, The Phantom followed on tiptoe. Noticing that the hall was deserted, he bent his ear to the keyhole. Two voices, one of them speaking with a distinct foreign accent, were talking in tones signifying that they had reason to be well pleased with themselves.

They were discussing the progress of Mr. Shei's adventure and congratulating themselves on the prospect of becoming immensely rich within a few days.

The Phantom, listening intently, was learning several facts of interest. The two speakers were addressing each other as Doctor Tagala and Mr. Slade, and he gathered from divers remarks that the latter was in charge of affairs at Azurecrest while Mr. Shei was watching developments in New York. Doctor Tagala seemed to be the scientist who had discovered the poison that was the chief factor in Mr. Shei's scheme.

Having absorbed a great deal of useful information, The Phantom raised his head from the keyhole. Then, he flexed his muscles and drew the automatic from his pocket. Here was his opportunity for putting his first plan to the test. It was cruder than the alternative ones, but it might also prove vastly more effective. His hand closed around the k.n.o.b. With automatic in one hand he softly pushed the door open, entering so silently that for several moments neither of the two men in the room was aware of the intrusion.

He gazed for an instant at the singularly repulsive face of the man addressed as Doctor Tagala, then gave his companion a fleeting glance of inspection, noticing that Slade had the strong jaw and aggressiveness of manners that usually go with a domineering personality. Only the eyes, shifty and unmagnetic, gave him a suspicion that there was a weak strain in the man's moral fiber.

Smiling affably, with every nerve in his body atingle, he advanced to the table.

"Good-evening, gentlemen," he said softly.

With a hoa.r.s.e cry Slade sprang from his chair, but Doctor Tagala gave the intruder only a cold, impersonal glance.

"Sit down, Slade," ordered The Phantom, "and both of you keep your hands on the table." He made a significant gesture with the automatic.

Slade stared and looked as if not quite certain that his eyes were to be trusted.

"How the devil did you get in?" he exclaimed explosively. He tried hard to get a grip on himself, but the twitching of the lines around his mouth showed that he was ill at ease. "But then," he added, steadying his voice with an effort, "I suppose anything is possible for The Gray Phantom."

"Ah, so you are The Gray Phantom." Doctor Tagala seemed mildly impressed. "I have heard a great deal of you, and I have felt some curiosity in regard to you. I must confess to a great disappointment, however. I did not think a man of your genius would descend to such crude methods. Of you I had expected subtlety and finesse. Bah!"

Slade was rapidly regaining his self-control, but he kept his hands obediently on the table. From time to time he cast an uneasy glance into the muzzle of The Phantom's pistol.

"I can't imagine how you got in," he admitted. "How you got past the picket fence, the dogs, and the watchmen is too much for me. But, now that you are here, what do you intend to do? I suppose it has something to do with Miss Hardwick?"

"Precisely, Slade."

The other sneered. "Don't you realize that there's nothing you can do?

What you heard over the telephone wire should have warned you to keep hands off. Miss Hardwick's life is absolutely in our power."

"For the present, yes; but I think the situation will soon be reversed."