The Thinking Machine paused just a fraction of a second.
"No," he said.
"Well, do you make it?" asked the warden. He was prepared to believe anything.
"That's my business," again said the prisoner.
The warden glared at the eminent scientist fiercely. He felt -- he knew -- that this man was making a fool of him, yet he didn't know how. If he were a real prisoner he would get the truth -- but, then, perhaps, those inexplicable things which had happened would not have been brought before him so sharply. Neither of the men spoke for a long time, then suddenly the warden turned fiercely and left the cell, slamming the door behind him. He didn't dare to speak, then.
He glanced at the clock. It was ten minutes to four. He had hardly settled himself in bed when again came that heart-breaking shriek through the prison. With a few muttered words, which, while not elegant, were highly expressive, he relighted his lantern and rushed through the prison again to the cell on the upper floor.
Again Ballard was crushing himself against the steel door, shrieking, shrieking at the top of his voice. He stopped only when the warden flashed his lamp in the cell.
"Take me out, take me out," he screamed. "I did it, I did it, I killed her. Take it away."
"Take what away?" asked the warden.
"I threw the acid in her face -- I did it -- I confess. Take me out of here."
Ballard's condition was pitiable; it was only an act of mercy to let him out into the corridor. There he crouched in a corner, like an animal at bay, and clasped his hands to his ears. It took half an hour to calm him sufficiently for him to speak. Then he told incoherently what had happened. On the night before at four o'clock he had heard a voice -- a sepulchral voice, muffled and wailing in tone.
"What did it say?" asked the warden, curiously.
"Acid -- acid -- acid!" gasped the prisoner. "It accused me. Acid! I threw the acid, and the woman died. Oh!" It was a long, shuddering wail of terror.
"Acid?" echoed the warden, puzzled. The case was beyond him.
"Acid. That's all I heard -- that one word, repeated several times. There were other things, too, but I didn't hear them."
"That was last night, eh?" asked the warden. "What happened to-night -- what frightened you just now?"
"It was the same thing," gasped the prisoner. "Acid -- acid -- acid!" He covered his face with his hands and sat shivering. "It was acid I used on her, but I didn't mean to kill her. I just heard the words. It was something accusing me -- accusing me." He mumbled, and was silent.
"Did you hear anything else?"
"Yes -- but I couldn't understand -- only a little bit -- just a word or two."
"Well, what was it?"
"I heard 'acid' three times, then I heard a long, moaning sound, then -- then -- I heard 'No. 8 hat.' I heard that twice."
"No. 8 hat," repeated the warden. "What the devil -- No. 8 hat? Accusing voices of conscience have never talked about No. 8 hats, so far as I ever heard. "
"He's insane," said one of the jailers, with an air of finality.
"I believe you," said the warden. "He must be. He probably heard something and got frightened. He's trembling now. No. 8 hat! What the--"
V.
When the fifth day of The Thinking Machine's imprisonment rolled around the warden was wearing a hunted look. He was anxious for the end of the thing. He could not help but feel that his distinguished prisoner had been amusing himself. And if this were so, The Thinking Machine had lost none of his sense of humor. For on this fifth day he flung down another linen note to the outside guard, bearing the words: "Only two days more." Also he flung down half a dollar.
Now the warden knew -- he knew -- that the man in Cell 13 didn't have any half dollars -- he couldn't have any half dollars, no more than he could have pen and ink and linen, and yet he did have them. It was a condition, not a theory; that is one reason why the warden was wearing a hunted look.
That ghastly, uncanny thing, too, about "Acid" and "No. 8 hat" clung to him tenaciously. They didn't mean anything, of course, merely the ravings of an insane murderer who had been driven by fear to confess his crime, still there were so many things that "didn't mean anything" happening in the prison now since The Thinking Machine was there.
On the sixth day the warden received a postal stating that Dr. Ransome and Mr. Fielding would be at Chisholm Prison on the following evening, Thursday, and in the event Professor Van Dusen had not yet escaped -- and they presumed he had not because they had not heard from him -- they would meet him there.
"In the event he had not yet escaped!" The warden smiled grimly. Escaped!
The Thinking Machine enlivened this day for the warden with three notes. They were on the usual linen and bore generally on the appointment at half-past eight o'clock Thursday night, which appointment the scientist had made at the time of his imprisonment.
On the afternoon of the seventh day the warden passed Cell 13 and glanced in. The Thinking Machine was lying on the iron bed, apparently sleeping lightly. The cell appeared precisely as it always did to a casual glance. The warden would swear that no man was going to leave it between that hour -- it was then four o'clock -- and half-past eight o'clock that evening.
On his way back past the cell the warden heard the steady breathing again, and coming close to the door looked in. He wouldn't have done so if The Thinking Machine had been looking, but now -- well, it was different.
A ray of light came through the high window and fell on the face of the sleeping man. It occurred to the warden for the first time that his prisoner appeared haggard and weary. Just then The Thinking Machine stirred slightly and the warden hurried on up the corridor guiltily. That evening after six o'clock he saw the jailer.
"Everything all right in Cell 13?" he asked.
"Yes, sir," replied the jailer. "He didn't eat much, though."
It was with a feeling of having done his duty that the warden received Dr. Ransome and Mr. Fielding shortly after seven o'clock. He intended to show them the linen notes and lay before them the full story of his woes, which was a long one. But before this came to pass, the guard from the river side of the prison yard entered the office.
"The arc light in my side of the yard won't light," he informed -the warden.
"Confound it, that man's a hoodoo," thundered the official. "Everything has happened since he's been here."
The guard went back to his post in the darkness, and the warden 'phoned to the electric light company.
"This is Chisholm Prison," he said through the 'phone. "Send three or four men down here quick, to fix an arc light."
The reply was evidently satisfactory, for the warden hung up the receiver and passed out into the yard. While Dr. Ransome and Mr. Fielding sat waiting the guard at the outer gate came in with a special delivery letter. Dr. Ransome happened to notice the address, and, when the guard went out, looked at the letter more closely.
"By George!" he exclaimed.
"What is it?" asked Mr. Fielding.
Silently the doctor offered the letter. Mr. Fielding examined it closely.
"Coincidence," he said. "It must be."
It was nearly eight o'clock when the warden returned to his office. The electricians had arrived in a wagon, and were now at work. The warden pressed the buzz-button communicating with the man at the outer gate in the wall.
"How many electricians came in?" he asked, over the short 'phone. "Four? Three workmen in jumpers and overalls and the manager? Frock coat and silk hat? All right. Be certain that only four go out. That's all."
He turned to Dr. Ransome and Mr. Fielding. "We have to be careful here -- particularly," and there was broad sarcasm in his tone, "since we have scientists locked up."