"I didn't expect you to," interrupted The Thinking Machine crustily. "I merely want to know if you noticed one."
"No," retorted Mr. Phillips shortly.
"And could you explain your precise feelings?" continued the scientist. "Did the effect of the bell's ringing seem to be entirely mental, or was it physical? In other words, was there any physical exaltation or depression when you heard it?"
"It would be rather difficult to say-even to myself," responded Mr. Phillips. "It always seemed to be a shock, but I suppose it was really a mental condition which reacted on my nerves."
The Thinking Machine walked over to the window and stood with his back to the others. For a minute or more he remained there, and three eager pairs of eyes were fixed inquiringly on the back of his yellow head. Beneath the irritated voice, behind the inscrutable face, in the disjointed questioning, they all knew intuitively there was some definite purpose, but to none came a glimmer of light as to its nature.
"I think, perhaps, the matter is all clear now," he remarked musingly at last. "There are two vital questions yet to be answered. If the first of these is answered in the affirmative, I know that a mind-I may say a Japanese mind-of singular ingenious quality conceived the condition which brought about this affair; if in the negative, the entire matter becomes ridiculously simple."
Mr. Phillips was leaning forward, listening greedily. There was hope and fear, doubt and confidence, eagerness and a certain tense restraint in his manner. Doctor Perdue was silent; Hatch merely waited.
"What made the bell ring?" demanded Mr. Phillips.
"I must find the answer to the two remaining questions first," returned The Thinking Machine.
"You mentioned a Japanese," said Mr. Phillips. "Do you suspect Mr. Matsumi of any connection with the-the mystery?"
"I never suspect persons of things, Mr. Phillips," said The Thinking Machine curtly. "I never suspect-I always know. When I know in this case I shall inform you. Mr. Hatch and I are going out for a few minutes. When we return the matter can be disposed of in ten minutes."
He led the way out and along the hall to the little room where the gong hung. Hatch closed the door as he entered. Then for the third time the scientist examined the bells. He struck the fifth violently time after time, and after each stroke he thrust an inquisitive nose almost against it and sniffed. Hatch stared at him in wonderment. When the scientist had finished he shook his head as if answering a question in the negative. With Hatch following he passed out into the street.
"What's the matter with Phillips?" the reporter ventured, as they reached the sidewalk.
"Scared, frightened," was the tart rejoinder. "He's merely morbidly anxious to account for the bell's ringing. If I had been absolutely certain before I came out I should have told him. I am certain now. You know, Mr. Hatch, when a thing is beyond immediate understanding it instantly suggests the supernatural to some minds. Mr. Phillips wouldn't confess it, but he sees back of the ringing of that bell some uncanny power-a threat, perhaps-and the thing has preyed upon him until he's nearly insane. When I can arrange to make him understand perfectly why the bell rings he will be all right again."
"I can readily see how the ringing of the bell strikes one as uncanny," Hatch declared grimly. "Have you an idea what causes it?"
"I know what causes it," returned the other irritably. "And if you don't know you're stupid."
The reporter shook his head hopelessly.
They crossed the street to the big apartment-house opposite, and entered. The Thinking Machine inquired for and was shown into the office of the manager. He had only one question.
"Was there a ball, or reception, or anything of that sort held in this building on Tuesday night, the eleventh of this month?" he inquired.
"No," was the response. "There has never been anything of that sort here."
"Thanks," said The Thinking Machine. "Good-day."
Turning abruptly he left the manager to figure that out as best he could, and, with Hatch following, ascended the stairs to the next floor. Here was a wide, airy hallway extending the full length of the building. The Thinking Machine glanced neither to right nor left; he went straight to the rear, where a plate-glass window enframed a panorama of the city. From where they stood the city's roofs slanted down toward the heart of the business district, half a mile away.
As Hatch looked on The Thinking Machine took out his watch and set it two and a half minutes forward, after which he turned and walked to the other end of the hall. Here, too, was a plate-glass window. For just a fraction of an instant he stood staring straight out at the Phillips' home across the way; then, without a word, retraced his steps down the stairs and into the street.
Hatch's head was overflowing with questions, but he choked them back and merely trailed along. They reentered the Phillips' house in silence. Doctor Perdue and Harvey Phillips met them in the hallway. An expression of infinite relief came into the physician's face at the sight of The Thinking Machine.
"I'm glad you're back so soon," he said quickly. "Here's a new development and a singular one." He referred evidently to a long envelope he held. "Step into the library here."
They entered, and Doctor Perdue carefully closed the door behind them.
"Just a few minutes ago Harvey received a sealed envelope by mail," he explained. "It inclosed this one, also sealed. He was going to show it to his father, but I didn't think it wise because of-because--"
The Thinking Machine took the envelope in one slender hand and examined it. It was a perfectly plain white one, and bore only a single line written in a small, copper-plate hand with occasional unexpected angles:
"To be opened when the fifth bell rings eleven times."
Something as nearly approaching complacent satisfaction as Hatch had ever seen overspread the petulant countenance of The Thinking Machine, and a long, aspirated "Ah!" escaped the thin lips. There was a hushed silence. Harvey Phillips, to whom nothing of the mystery was known beyond the actual death of Wagner, sought to read what it all meant in Doctor Perdue's face. In turn Doctor Perdue's eyes were fastened on The Thinking Machine.
"Of course, you don't know whom this is from, Mr. Phillips?" inquired the scientist of the young man.
"I have no idea," was the reply. "It seemed to amaze Doctor Perdue here, but, frankly, I can't imagine why."
"You don't know the handwriting?"
"No."
"Well, I do," declared The Thinking Machine emphatically. "It's Mr. Matsumi's." He glared at the physician. "And in it lies the key to this affair of the bell. The mere fact that it came at all proves everything as I saw it."
"But it can't be from Matsumi," protested the young man. "The postmark on the outside was Cleveland."
"That means merely that he is running away to escape arrest on a charge of murder."
"Then Matsumi killed Wagner?" Hatch asked quickly.
"I didn't say it was a confession," responded the scientist curtly. "It is merely a history of the bell. I dare say--"
Suddenly the door was thrown open and Mrs. Phillips entered. Her face was ashen.
"Doctor, he is worse-sinking rapidly!" she gasped. "Please come!"
Doctor Perdue glanced from her pallid face to the impassive Thinking Machine.
"Van Dusen," he said solemnly, "if you can do anything to explain this thing, do it now. I know it will save a man's reason-it might save his life."
"Is he conscious?" inquired the scientist of Mrs. Phillips.
"No, he seems to have utterly collapsed," she explained. "I was talking to him when suddenly he sat up in bed as if listening, then shrieked something I didn't understand and fell back unconscious."
Doctor Perdue was dragged out of the room by the wife and son. The Thinking Machine glanced at his watch. It was three and a half minutes past four o'clock. He nodded, then turned to Hatch.
"Please go into the little room and close the window," he instructed. "Mr. Phillips has heard the bell again, and I imagine Doctor Perdue needs me. Meanwhile, put this envelope in your pocket." And he handed to Hatch the mysterious sealed packet.
It was twenty minutes past nine o'clock that evening. In the little room where the gong hung were Franklin Phillips, pale and weak, but eager; Doctor Perdue, The Thinking Machine, Harvey Phillips and Hatch. For four hours Doctor Perdue and the scientist had labored over the unconscious financier, and finally a tinge of color returned to the pale lips; then came consciousness.
"It was my suggestion, Mr. Phillips, that we are here," explained The Thinking Machine quietly. "I want to show you just why and how the bell rings, and incidentally clear up the other points of the mystery. Now, if I should tell you that the bell will sound a given number of times at a given instant, and it should sound, you would know that I was aware of the cause?"
"Certainly," assented Mr. Phillips eagerly.