The doctor left the house. Muller smiled bitterly as he closed the
door behind him, and murmured to himself: "Indeed, I do not forget
it, and that is why I shall take this matter into my own hands. But
the Kniepp case is not closed yet, by any means."

When he returned to the study he saw Johann sitting quietly in a
corner, shaking his head, as if trying to understand it all. Horn
was bending over a sheet of writing paper which lay before the dead
man. Fellner must have been busy at his desk when the bullet
penetrated his heart. His hand in dying had let fall the pen,
which had drawn a long black mark across the bottom of the sheet.
One page of the paper was covered with a small, delicate handwriting.

Horn called up the detective, and together they read the following words:

"Dear Friend: -

"He challenged me - pistols - it means life or death. My enemy is
very bitter. But I am not ready to die yet. And as I know that I
would be the one to fall, I have refused the duel. That will help
me little, for his revenge will know how to find me. I dare not be
a moment without a weapon now - his threats on my refusal let me
fear the worst. I have an uncanny presentiment of evil. I shall
leave here to-morrow. With the excuse of having some pressing
family affair to attend to, I have secured several days' leave.
Of course I do not intend to return. I am hoping that you will
come here and break up my establishment in my stead. I will tell
you everything else when I see you. I am in a hurry now, for there
is a good deal of packing to do. If anything should happen to me,
you will know who it is who is responsible for my death. His