ne
down without a sound. The scout thought a moment, then seized his
sweep, and drove his skiff square across the river. Had the men gone
out towards the middle? But Chippy opened fresh sweeps of the starlit
stream, and all empty. Save for himself, there did not seem to be a
single floating thing in the neighbourhood.

Now, in working across, Chippy had also gone down with the stream, so
that by the time he was well out he had gained a point directly in
front of the warehouse. He glanced towards the dark mass at the
water's edge, and started. A pin-point of light flashed out at its
base far below window or doorway. The light burned steadily for a few
seconds, then went out as suddenly as it appeared.

'Looks to me as if some'dy struck a match over theer,' reflected
Chippy. 'But who? The water looked empty enough. I'll have a look.'

He worked his boat round, and drove it steadily towards the great
building, shaping his course a little upstream, in order to bring
himself above it once more. He watched closely as he sculled, and when
he checked his way not ten yards from the bank he was quite certain of
two things: he had not seen the light again, and he had not seen any
boat leave the front of the warehouse.

He let himself drift slowly down, staring and staring, and full of
wonder. His eyes were now so used to the starshine on the river that
he could see the water in front of the building like a smooth, pale
plain, and it was empty--it was perfectly empty. Who had struck that
light about the water-level? It was all very strange and mysterious.

Chippy let his craft drift. It moved slowly on the slow-running
stream, but presently it was under the shadow of the lofty wall, and as
it slid along, Chippy looked out more sharply than ever for the source
of that strange light.

He stood in the stern of the boat drifting down in complete silence,
with not even the gurgle of the sweep to betray his presence. And to
this complete silence Chippy owed the discovery which he made about
midway of the river-front.

He was staring straight at the blackness of the wall, when suddenly a
light appeared in it. To his immense surprise, he found himself
looking up a kind of long, arched tunnel, at whose farther end a man
stood in a boat, a light in his hand. Only for an instant did Chippy
behold this strange vision. His skiff drifted on, and he was faced
once more by the darkness of the solid wall.

Chippy drew a