I have
a morbid fear of misdirecting you; but even if I am in error, you may
know the right drawer by its contents: some powders, a phial and a
paper book. This drawer I beg of you to carry back with you to Cavendish
Square exactly as it stands.

"That is the first part of the service: now for the second. You should
be back, if you set out at once on the receipt of this, long before
midnight; but I will leave you that amount of margin, not only in
the fear of one of those obstacles that can neither be prevented nor
foreseen, but because an hour when your servants are in bed is to be
preferred for what will then remain to do. At midnight, then, I have to
ask you to be alone in your consulting room, to admit with your own hand
into the house a man who will present himself in my name, and to place
in his hands the drawer that you will have brought with you from my
cabinet. Then you will have played your part and earned my gratitude
completely. Five minutes afterwards, if you insist upon an explanation,
you will have understood that these arrangements are of capital
importance; and that by the neglect of one of them, fantastic as they
must appear, you might have charged your conscience with my death or the
shipwreck of my reason.

"Confident as I am that you will not trifle with this appeal, my heart
sinks and my hand trembles at the bare thought of such a possibility.
Think of me at this hour, in a strange place, labouring under a
blackness of distress that no fancy can exaggerate, and yet well aware
that, if you will but punctually serve me, my troubles will roll away
like a story that is told. Serve me, my dear Lanyon and save

"Your friend,

"H.J.

"P.S.--I had already sealed this up when a fresh terror struck upon my
soul. It is possible that the post-office may fail me, and this letter
not come into your hands until to-morrow morning. In that case, dear
Lanyon, do my errand when it shall be most convenient for you in the
course of the day; and once more expect my messenger at midnight. It may
then already be too late; and if that night passes without event, you
will know that you have seen the last of Henry Jekyll."

Upon the reading of this letter, I made sure my colleague was insane;
but till that was proved beyond the possibility of doubt, I felt bound
to do as he requested. The less I understood of this farrago, the less
I was in a position to judge of its importance; and an appeal so
worded could not be