om the crypt of
AEsculapius, and led the way into the secret chamber in which the
hypnotic suggestion of love had been put into operation. At this time
it appeared simply as an ordinary room, the staging and curtains
having been removed.

"Be seated, Mr. Barnes," said the Doctor, "and listen to me. You are
laboring under a misapprehension, or else you have not told me all
that you know. A most curious suspicion has been aroused in your mind.
Upon what facts is it based?"

"Perhaps it will be best for me to explain. I must again refer to the
fact that your first wife was supposed to have died of diphtheria.
Your second wife falls a victim to the same malady. It is uncommon in
adults. This of itself might be but a coincidence. But when I know
that, on a given day, I revealed to your wife the truth about Leon,
which you had carefully hidden from her for so many years, and when I
subsequently discover that Madame was attacked by this disease on the
very night following her visit to my office, suspicion was
inevitable."

"As you insist upon going back to that old case, let me ask you how
you can suppose that I induced the disease at that time?"

"Just as you have done now. By using the diphtheria bacillus."

"You forget, or you do not know, that the bacillus of diphtheria was
not discovered until Klebs found it in 1883, and the fact was not
known until Loeffler published it in 1884. Now my wife died in 1873."

"True, these scientists made their discoveries at the time which you
name, but I feel certain that you had anticipated them. You are
counted the most skilful man of the day, and I believe that you know
more than has been learned by others."

"Your compliment is a doubtful one. But I will not dispute with you. I
will grant, for the sake of argument, that your suspicion is natural.
You cannot proceed against me merely upon suspicion. At least you
should not do so."

"My suspicion is shared by another, whose mind it has entered by a
different channel."

"Who is this other?"

"Your son!"

"What do you say? Leon suspects that I have committed a crime? This is
terrible! But why? Why, in the name of heaven, should he harbor such a
thought against me?" The Doctor was unusually excited.

"He saw you take the culture tube, containing the bacillus, out of the
laboratory."

"You say Leon saw me take a culture tube from the laboratory?" The
Doctor spoke the words separately, with a pause between each, as
though s