on the bar on the inside and had my
head below the gap ere the driver could possibly have seen me.

"Stay where you are until he passes," hissed my companion, below.
"There is a row of kegs under you."

The sound of the motor passing outside grew loud--louder--then began
to die away. I felt about with my left foot, discerned the top of a
keg, and dropped, panting, beside Smith.

"Phew!" I said--"that was a close thing! Smith--how do we know--?"

"That we have followed the right car?" he interrupted. "Ask yourself
the question: what would any ordinary man be doing motoring in a place
like this at two o'clock in the morning?"

"You are right, Smith," I agreed. "Shall we get out again?"

"Not yet. I have an idea. Look yonder."

He grasped my arm, turning me in the desired direction.

Beyond a great expanse of unbroken darkness a ray of moonlight slanted
into the place wherein we stood, spilling its cold radiance upon rows
of kegs.

"That's another door," continued my friend. I now began dimly to
perceive him beside me. "If my calculations are not entirely wrong, it
opens on a wharf gate--"

A steam siren hooted dismally, apparently from quite close at hand.

"I'm right!" snapped Smith. "That turning leads down to the gate. Come
on, Petrie!"

He directed the light of the electric torch upon a narrow path through
the ranks of casks, and led the way to the farther door. A good two
feet of moonlight showed along the top. I heard Smith straining;
then--

"These kegs are all loaded with grease," he said, "and I want to
reconnoitre over that door."

"I am leaning on a crate which seems easy to move," I reported. "Yes,
it's empty. Lend a hand."

We grasped the empty crate, and, between us, set it up on a solid
pedestal of casks. Then Smith mounted to this observation platform and
I scrambled up beside him, and looked down upon the lane outside.

It terminated as Smith had foreseen at a wharf gate some six feet to
the right of our post. Piled up in the lane beneath us, against the
warehouse door, was a stack of empty casks. Beyond, over the way, was
a kind of ramshackle building that had possibly been a dwelling-house
at some time. Bills were stuck in the ground-floor windows indicating
that the three floors were to let as offices; so much was discernible
in that reflected moonlight.

I could hear the tide lapping upon the wharf, could feel the chill
from the near river and hear the vague noises which, night n