“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.