's edge at low tide.

It was impossible even to hazard a guess what kind of a weapon had
inflicted the death wound. But it had not been a clean, stabbing wound
to the heart. The wound itself must have been a long gash downward along
the breast, for the shirt and waistcoat had been curiously ripped and
torn. And possibly the weapon might be found in the grass where the body
had lain.

I quietly moved back and forth among the group of men, searching for the
gleam of moonlight upon a knife blade. It didn't reveal itself, however,
and there seemed no course but to wait for daylight. But as I was about
to give up the search my eye caught the glimpse of something white,
half-hidden in the grass in the direction of the house.

I quietly picked it up, saw that it was a folded piece of heavy paper or
parchment, and slipped it into my pocket. Then I rejoined the little
crowd of guests.

"Good Lord, what can we do...?" Pescini was saying excitedly. "The lake
can't be dragged until to-morrow. There's no use to post guards around
this big house--the thickets are so heavy that any one could steal
through almost any place. We've got the road guarded--and the officers
won't come till to-morrow. It's true that a couple of us could stand
guard here----"

"I don't see what good it would do," Nopp replied. "The murderer would
have no cause to come back again. I suggest we go to the house and get
what rest we can. We may have to make some posses in the morning."

In the privacy of my own room I took from my pocket the paper I had
found. It proved to be of heavy parchment, whitened by time; and I felt
at once I was running on a true scent.

There could be little doubt as to the age of the document. The ink was
fading, the handwriting itself was in the style of long ago. The fact
that the script was scratchy and uncertain, indicated that a man of
meager education had written it. It was, however, perfectly legible. I
judged that the date of the missive was at least ten or twenty years
prior to the civil war.

Across the top of the page were written the words, referring evidently
to the script beneath, "Sworn by the Book." At the very bottom was the
cryptic phrase "int F. T." And the following, mysterious column lay
between:

aned
dqbo
aqcd
trkm
fipj
dqbo
scno
ohuy
wvyn
dljn
dtht

Of course no kind of an explanation presented itself at first. I took it
to a mirror, tri