Stephen Roland turned quietly around and shook the hand from his shoulder. It was evident that he recognized Stratton instantly.

"Is this a Chicago joke?" asked the doctor.

"If it is, Mr. Roland, I think you will find it a very serious one."

"Aren't you afraid that you may find it a serious one?"

"I don't see why I should have any fears in the premises," answered the newspaper man.

"My dear sir, do you not realize that I could knock you down or shoot you dead for what you have done, and be perfectly justified in doing so?"

"If you either knock or shoot," replied the other, "you will have to do it very quickly, for, in the language of the wild and woolly West, I've got the drop on you. In my coat pocket is a cocked revolver with my forefinger on the trigger. If you make a hostile move I can let daylight through you so quickly that you won't know what has struck you."

"Electric light, I think you mean," answered the doctor, quietly. "Even a Chicago man might find it difficult to let daylight through a person at this time in the evening. Now, this sort of thing may be Chicago manners, but I assure you it will not go down here in Cincinnati. You have rendered yourself liable to the law if I cared to make a point of it, but I do not. Come back with me to my study. I would like to talk with you."

Stratton began to feel vaguely that he had made a fool of himself. His scheme had utterly failed. The doctor was a great deal cooler and more collected than he was. Nevertheless, he had a deep distrust of the gentleman, and he kept his revolver handy for fear the other would make a dash to escape him. They walked back without saying a word to each other until they came to the doctor's office. Into the house they entered, and the doctor bolted the door behind them. Stratton suspected that very likely he was walking into a trap, but he thought he would be equal to any emergency that might arise. The doctor walked into the study, and again locked the door of that. Pulling down the blinds, he turned up the gas to its full force and sat down by a table, motioning the newspaper man to a seat on the other side.

"Now," he said calmly to Stratton, "the reason I did not resent your unwarrantable insult is this: You are conscientiously trying to get at the root of this mystery. So am I. Your reason is that you wish to score a victory for your paper. My motive is entirely different, but our object is exactly the same. Now, by some strange combination of circumstances you have come to the conclusion that I committed the crime. Am I right?"

"You are perfectly correct, doctor," replied Stratton.

"Very well, then. Now, I assure you that I am entirely innocent. Of course, I appreciate the fact that this assurance will not in the slightest degree affect your opinion, but I am interested in knowing why you came to your conclusion, and perhaps by putting our heads together, even if I dislike you and you hate me, we may see some light on this matter that has hitherto been hidden. I presume you have no objection at all to co-operate with me?"

"None in the least," was the reply.

"Very well, then. Now, don't mind my feelings at all, but tell me exactly why you have suspected me of being a murderer."

"Well," answered Stratton, "in the first place we must look for a motive. It seems to me that you have a motive for the crime."

"And might I ask what that motive is, or was?"

"You will admit that you disliked Brenton?"

"I will admit that, yes."

"Very well. You will admit also that you were—well, how shall I put it?—let us say, interested in his wife before her marriage?"

"I will admit that; yes."

"You, perhaps, will admit that you are interested in her now?"

"I do not see any necessity for admitting that; but still, for the purpose of getting along with the case, I will admit it. Go on."

"Very good. Here is a motive for the crime, and a very strong one. First, we will presume that you are in love with the wife of the man who is murdered. Secondly, supposing that you are mercenary, quite a considerable amount of money will come to you in case you marry Brenton's widow. Next, some one at that table poisoned him. It was not Mrs. Brenton, who poured out the cup of coffee. The cup of coffee was placed before Brenton, and my opinion is that, until it was placed there, there was no poison in that cup. The doomed man was entirely unsuspicious, and therefore it was very easy for a person to slip enough poison in that cup unseen by anybody at that table, so that when he drank his coffee nothing could have saved him. He rose from the table feeling badly, and he went to his room and died. Now, who could have placed that poison in his cup of coffee? It must have been one of the two that sat at his right and left hand. A young lady sat at his right hand. She certainly did not commit the crime. You, Stephen Roland, sat at his left hand. Do you deny any of the facts I have recited?"

"That is a very ingenious chain of circumstantial evidence. Of course, you do not think it strong enough to convict a man of such a serious crime as murder?"

"No; I quite realize the weakness of the case up to this point. But there is more to follow. Fourteen days before that dinner you purchased at the drug store on the corner of Blank Street and Nemo Avenue thirty grains of morphia. You had the poison put up in capsules of five grains each. What do you say to that bit of evidence added to the circumstantial chain which you say is ingenious?"

The doctor knit his brows and leaned back in his chair.

"By the gods!" he said, "you are right. I did buy that morphia. I remember it now. I don't mind telling you that I had a number of experiments on hand, as every doctor has, and I had those capsules put up at the drug store, but this tragedy coming on made me forget all about the matter."

"Did you take the morphia with you, doctor?"

"No, I did not. And the box of capsules, I do not think, has been opened. But that is easily ascertained."

The doctor rose, went to his cabinet, and unlocked it. From a number of packages he selected a small one, and brought it to the desk, placing it before the reporter.

"There is the package. That contains, as you say, thirty grains of morphia in half a dozen five-grain capsules. You see that it is sealed just as it left the drug store. Now, open it and look for yourself. Here are scales; if you want to see whether a single grain is missing or not, find out for yourself.

"Perhaps," said the newspaper man, "we had better leave this investigation for the proper authorities."

"Then you still believe that I am the murderer of William Brenton?"

"Yes, I still believe that."

"Very well; you may do as you please. I think, however, in justice to myself, you should stay right here, and see that this box is not tampered with until the proper authorities, as you say, come."

Then, placing his hand on the bell, he continued—"Whom shall I send for? An ordinary policeman, or some one from the central office? But, now that I think of it, here is a telephone. We can have any one brought here that you wish. I prefer that neither you nor I leave this room until that functionary has appeared. Name the authority you want brought here," said the doctor, going to the telephone, "and I will have him here if he is in town."

The newspaper man was nonplussed. The Doctor's actions did not seem like those of a guilty man. If he were guilty he certainly had more nerve than any person Stratton had ever met. So he hesitated. Then he said—

"Sit down a moment, doctor, and let us talk this thing over."

"Just as you say," remarked Roland, drawing up his chair again.

Stratton took the package, and looked it over carefully. It was certainly just in the condition in which it had left the drug store; but still, that could have been easily done by the doctor himself.

"Suppose we open this package?" he said to Roland.

"With all my heart," said the doctor, "go ahead;" and he shoved over to him a little penknife that was on the table.

The reporter took the package, ran the knife around the edge, and opened it. There lay six capsules, filled, as the doctor had said. Roland picked up one of them, and looked at it critically.

"I assure you," he said, "although I am quite aware you do not believe a word I say, that I have not seen those capsules before."

He drew towards him a piece of paper, opened the capsule, and, let the white powder fall on the paper. He looked critically at the powder, and a shade of astonishment came over his face. He picked up the penknife, took a particle on the tip of it, and touched it with his tongue.

"Don't fool with that thing!" said Stratton.

"Oh, my dear fellow," he said, "morphia is not a poison in small quantities."

The moment he had tasted it, however, he suddenly picked up the paper, put the five grains on his tongue, and swallowed them.

Instantly the reporter sprang to his feet. He saw at once the reason for all the assumed coolness. The doctor was merely gaining time in order to commit suicide.

"What have you done?" cried the reporter.

"Done, my dear fellow? nothing very much. This is not morphia; it is sulphate of quinine."