“In the front window,” resumed Craig, “just as you enter, I noticed one of those little oblong signs printed neatly in black on white—­’Dr. Vernon Harris, M. D.’  You recall that the letter said something about a doctor who was very friendly with that clique the writer mentioned?  It’s even money that this Harris is the one the writer meant.  I suppose he is the ‘house physician’ of this gilded palace.”

Clare nodded appreciatively.  “Quite right,” she agreed.  “Just how do you think he might be involved?”

“Of course I can’t say.  But I think, without going any further, that a man like that in a place like this will bear watching anyway, without our needing more than the fact that he is here.  Naturally we don’t know anything about him as a doctor, but he must have some training; and in an environment like this—­well, a little training may be a dangerous thing.”

“The letter said something about drugs,” mused Clare.

“Yes,” added Kennedy.  “As you know, alcohol is absolutely necessary to a thing like this.  Girls must keep gay and attractive; they must meet men with a bright, unfaltering look, and alcohol just dulls the edge of conscience.  Besides, look over that wine list—­it fills the till of the Montmartre, judging by the prices.  But then, alcohol palls when the pace is as swift as it seems to be here.  Even more essential are drugs.  You know, after all, it is no wonder so many drug fiends and drunkards are created by this life.  Now, a doctor who is not over-scrupulous, and he would have to be not over-scrupulous to be here at all, would find a gold mine in the dispensing of drugs and the toning up of drug fiends and others who have been going the pace too rapidly.”

“Yes,” she said.  “We have found that some of these doctors are a great factor in the life of various sections of the city where they hang out.  I know one who is deeply in the local politics and boasts that any resort that patronizes him is immune.  Yes, that’s a good point about Dr. Harris.”

“I suppose your investigators have had more or less to do with watching the progress of drug habits?” ventured Craig.

“Very much,” she replied, catching the drift of his remarks.  “We have found, for instance, that there are a great many cases where it seems that drugs have been used in luring young and innocent girls.  Not the old knockout drops—­chloral, you know—­but modern drugs, not so powerful, perhaps, but more insidious, and in that respect, I suppose, more dangerous.  There are cocaine fiends, opium smokers; oh, lots of them.  But those we find in the slums mostly.  Still, I suppose there are all kinds of drugs up here in the White Light District—­belladonna to keep the eyes bright, arsenic to whiten the complexion, and so on.”

“Yes,” asserted Craig.  “This section of the city may not be so brutal in its drug taking as others, but it is here—­yes, and it is over on Fifth Avenue, too, right in society.  Before we get through I’m sure we’ll both learn much more than we even dream of now.”