As the horror of it all dawned on me, I hated Armstrong worse than ever, hated Whitecap, hated the man higher up, whoever he might be, who was enriching himself out of the defective, as well as the weakling, and the vicious—all three typified by Snowbird, Armstrong and Whitecap.

Having no other place to go, pending further developments of the publicity we had given the drug war in the Star, Kennedy and I decided on a walk home in the bracing night air.

We had scarcely entered the apartment when the hall boy called to us frantically: "Some one's been trying to get you all over town, Professor Kennedy. Here's the message. I wrote it down. An attempt has been made to poison Mrs. Sutphen. They said at the other end of the line that you'd know."

We faced each other aghast.

"My God!" exclaimed Kennedy. "Has that been the effect of our story,
Walter? Instead of smoking out anyone—we've almost killed some one."

As fast as a cab could whisk us around to Mrs. Sutphen's we hurried.

"I warned her that if she mixed up in any such fight as this she might expect almost anything," remarked Mr. Sutphen nervously, as he met us in the reception room. "She's all right, now, I guess, but if it hadn't been for the prompt work of the ambulance surgeon I sent for, Dr. Coleman says she would have died in fifteen minutes."

"How did it happen?" asked Craig.

"Why, she usually drinks a glass of vichy and milk before retiring," replied Mr. Sutphen. "We don't know yet whether it was the vichy or the milk that was poisoned, but Dr. Coleman thinks it was chloral in one or the other, and so did the ambulance surgeon. I tell you I was scared. I tried to get Coleman, but he was out on a case, and I happened to think of the hospitals as probably the quickest. Dr. Coleman came in just as the young surgeon was bringing her around. He—oh, here he is now."

The famous doctor was just coming downstairs. He saw us, but, I suppose, inasmuch as we did not belong to the Sutphen and Coleman set, ignored us. "Mrs. Sutphen will be all right now," he said reassuringly as he drew on his gloves. "The nurse has arrived, and I have given her instructions what to do. And, by the way, my dear Sutphen, I should advise you to deal firmly with her in that matter about which her name is appearing in the papers. Women nowadays don't seem to realize the dangers they run in mixing in in all these reforms. I have ordered an analysis of both the milk and vichy, but that will do little good unless we can find out who poisoned it. And there are so many chances for things like that, life is so complex nowadays—"

He passed out with scarcely a nod at us. Kennedy did not attempt to question him. He was thinking rapidly.

"Walter, we have no time to lose," he exclaimed, seizing a telephone that stood on a stand near by. "This is the time for action. Hello—Police Headquarters, First Deputy O'Connor, please."

As Kennedy waited I tried to figure out how it could have happened. I wondered whether it might not have been Mrs. Garrett. Would she stop at anything if she feared the loss of her favorite drug? But then there were so many others and so many ways of "getting" anybody who interfered with the drug traffic that it seemed impossible to figure it out by pure deduction.

"Hello, O'Connor," I heard Kennedy say; "you read that story in the Star this morning about the drug fiends at that Broadway cabaret? Yes? Well, Jameson and I wrote it. It's part of the drug war that Mrs. Sutphen has been waging. O'Connor, she's been poisoned—oh, no—she's all right now. But I want you to send out and arrest Whitecap and that fellow Armstrong immediately. I'm going to put them through a scientific third degree up in the laboratory to-night. Thank you. No—no matter how late it is, bring them up."

Dr. Coleman had gone long since, Mr. Sutphen had absolutely no interest further than the recovery of Mrs. Sutphen just now, and Mrs. Sutphen was resting quietly and could not be seen. Accordingly Kennedy and I hastened up to the laboratory to wait until O'Connor could "deliver the goods."

It was not long before one of O'Connor's men came in with Whitecap.

"While we're waiting," said Craig, "I wish you would just try this little cut-out puzzle."

I don't know what Whitecap thought, but I know I looked at Craig's invitation to "play blocks" as a joke scarcely higher in order than the number repetition of Snowbird. Whitecap did it, however, sullenly, and under compulsion, in, I should say about two minutes.

"I have Armstrong here myself," called out the voice of our old friend
O'Connor, as he burst into the room.

"Good!" exclaimed Kennedy. "I shall be ready for him in just a second. Have Whitecap held here in the anteroom while you bring Armstrong into the laboratory. By the way, Walter, that was another of the Binet tests, putting a man at solving puzzles. It involves reflective judgment, one of the factors in executive ability. If Whitecap had been defective, it would have taken him five minutes to do that puzzle, if at all. So you see he is not in the class with Miss Sawtelle. The test shows him to be shrewd. He doesn't even touch his own dope. Now for Armstrong."

I knew enough of the underworld to set Whitecap down, however, as a "lobbygow"—an agent for some one higher up, recruiting both the gangs and the ranks of street women.

Before us, as O'Connor led in Armstrong, was a little machine with a big black cylinder. By means of wires and electrodes Kennedy attached it to Armstrong's chest.

"Now, Armstrong," he began in an even tone, "I want you to tell the truth—the whole truth. You have been getting heroin tablets from Whitecap."

"Yes, sir," replied the dope fiend defiantly.

"To-day you had to get them elsewhere."

No answer.

"Never mind," persisted Kennedy, still calm, "I know. Why, Armstrong, you even robbed that girl of twenty-five tablets."

"I did not," shot out the answer.

"There were twenty-five short," accused Kennedy.

The two faced each other. Craig repeated his remark.

"Yes," replied Armstrong, "I held out the tablets, but it was not for myself, I can get all I want. I did it because I didn't want her to get above seventy-five a day. I have tried every way to break her of the habit that has got me—and failed. But seventy-five—is the limit!"

"A pretty story!" exclaimed O'Connor.

Craig laid his hand on his arm to check him, as he examined a record registered on the cylinder of the machine.

"By the way, Armstrong, I want you to write me out a note that I can use to get a hundred heroin tablets. You can write it all but the name of the place where I can get them."

Armstrong was on the point of demurring, but the last sentence reassured him. He would reveal nothing by it—yet.

Still the man was trembling like a leaf. He wrote:

"Give Whitecap one hundred shocks—A Victim."

For a moment Kennedy studied the note carefully. "Oh—er—I forgot,
Armstrong, but a few days ago an anonymous letter was sent to Mrs.
Sutphen, signed 'A Friend.' Do you know anything about it?"

"A note?" the man repeated. "Mrs. Sutphen? I don't know anything about any note, or Mrs. Sutphen either."

Kennedy was still studying his record. "This," he remarked slowly, "is what I call my psychophysical test for falsehood. Lying, when it is practiced by an expert, is not easily detected by the most careful scrutiny of the liar's appearance and manner.

"However, successful means have been developed for the detection of falsehood by the study of experimental psychology. Walter, I think you will recall the test I used once, the psychophysical factor of the character and rapidity of the mental process known as the association of ideas?"

I nodded acquiescence.

"Well," he resumed, "in criminal jurisprudence, I find an even more simple and more subjective test which has been recently devised. Professor Stoerring of Bonn has found out that feelings of pleasure and pain produce well-defined changes in respiration. Similar effects are produced by lying, according to the famous Professor Benussi of Graz.

"These effects are unerring, unequivocal. The utterance of a false statement increases respiration; of a true statement decreases. The importance and scope of these discoveries are obvious."

Craig was figuring rapidly on a piece of paper. "This is a certain and objective criterion," he continued as he figured, "between truth and falsehood. Even when a clever liar endeavors to escape detection by breathing irregularly, it is likely to fail, for Benussi has investigated and found that voluntary changes in respiration don't alter the result. You see, the quotient obtained by dividing the time of inspiration by the time of expiration gives me the result."

He looked up suddenly. "Armstrong, you are telling the truth about some things—downright lies about others. You are a drug fiend—but I will be lenient with you, for one reason. Contrary to everything that I would have expected, you are really trying to save that poor half-witted girl whom you love from the terrible habit that has gripped you. That is why you held out the quarter of the one hundred tablets. That is why you wrote the note to Mrs. Sutphen, hoping that she might be treated in some institution."

Kennedy paused as a look of incredulity passed over Armstrong's face.

"Another thing you said was true," added Kennedy. "You can get all the heroin you want. Armstrong, you will put the address of that place on the outside of the note, or both you and Whitecap go to jail. Snowbird will be left to her own devices—she can get all the 'snow,' as some of you fiends call it, that she wants from those who might exploit her."

"Please, Mr. Kennedy," pleaded Armstrong.

"No," interrupted Craig, before the drug fiend could finish. "That is final. I must have the name of that place."

In a shaky hand Armstrong wrote again. Hastily Craig stuffed the note into his pocket, and ten minutes later we were mounting the steps of a big brownstone house on a fashionable side street just around the corner from Fifth Avenue.

As the door was opened by an obsequious colored servant, Craig handed him the scrap of paper signed by the password, "A Victim."

Imitating the cough of a confirmed dope user, Craig was led into a large waiting room.

"You're in pretty bad shape, sah," commented the servant.

Kennedy nudged me and, taking the cue, I coughed myself red in the face.

"Yes," he said. "Hurry—please."

The servant knocked at a door, and as it was opened we caught a glimpse of Mrs. Garrett in negligee.

"What is it, Sam?" she asked.

"Two gentlemen for some heroin tablets, ma'am."

"Tell them to go to the chemical works—not to my office, Sam," growled a man's voice inside.

With a quick motion, Kennedy had Mrs. Garrett by the wrist.

"I knew it," he ground out. "It was all a fake about how you got the habit. You wanted to get it, so you could get and hold him. And neither one of you would stop at anything, not even the murder of your sister, to prevent the ruin of the devilish business you have built up in manufacturing and marketing the stuff."

He pulled the note from the hand of the surprised negro. "I had the right address, the place where you sell hundreds of ounces of the stuff a week—but I preferred to come to the doctor's office where I could find you both."

Kennedy had firmly twisted her wrist until, with a little scream of pain, she let go the door handle. Then he gently pushed her aside, and the next instant Craig had his hand inside the collar of Dr. Coleman, society physician, proprietor of the Coleman Chemical Works downtown, the real leader of the drug gang that was debauching whole sections of the metropolis.