y, looking about me at the
ships, thinking of the girl Flora, of life's chances--and, do you know,
it was very simple."

"What was very simple?" I asked innocently.

"The mystery."

"They generally are that," I said.

Marlow eyed me for a moment in a peculiar manner.

"Well, I have discovered the mystery of Powell's disappearances. The
fellow used to run into one of these narrow tidal creeks on the Essex
shore. These creeks are so inconspicuous that till I had studied the
chart pretty carefully I did not know of their existence. One afternoon,
I made Powell's boat out, heading into the shore. By the time I got
close to the mud-flat his craft had disappeared inland. But I could see
the mouth of the creek by then. The tide being on the turn I took the
risk of getting stuck in the mud suddenly and headed in. All I had to
guide me was the top of the roof of some sort of small building. I got
in more by good luck than by good management. The sun had set some time
before; my boat glided in a sort of winding ditch between two low grassy
banks; on both sides of me was the flatness of the Essex marsh, perfectly
still. All I saw moving was a heron; he was flying low, and disappeared
in the murk. Before I had gone half a mile, I was up with the building
the roof of which I had seen from the river. It looked like a small
barn. A row of piles driven into the soft bank in front of it and
supporting a few planks made a sort of wharf. All this was black in the
falling dusk, and I could just distinguish the whitish ruts of a cart-
track stretching over the marsh towards the higher land, far away. Not a
sound was to be heard. Against the low streak of light in the sky I
could see the mast of Powell's cutter moored to the bank some twenty
yards, no more, beyond that black barn or whatever it was. I hailed him
with a loud shout. Got no answer. After making fast my boat just
astern, I walked along the bank to have a look at Powell's. Being so
much bigger than mine she was aground already. Her sails were furled;
the slide of her scuttle hatch was closed and padlocked. Powell was
gone. He had walked off into that dark, still marsh somewhere. I had
not seen a single house anywhere near; there did not seem to be any human
habitation for miles; and now as darkness fell denser over the land I
couldn't see the glimmer of a single light. However, I supposed that
there must be some village or hamlet not very far away; o