business."

"Isn't it? Well, that lorry went on out of sight. I waited there until
after six, and four more passed. About eleven o'clock No. 6 with the
clean-shaven driver passed out, loaded, so far as I could see, with
firewood. That was the one that passed in empty at nine. Then there was
a pause until half past two, when your friend returned with his lorry.
It was empty this time, and it was still No. 1. But I'm blessed,
Merriman, if he didn't stop at the same place and change the number back
to 4!"

"Lord!" said Merriman tersely, now almost as much interested as his
friend.

"It only took a couple of seconds, and then the machine lumbered on
towards the mill. I was pretty excited, I can tell you, but I decided to
sit tight and await developments. The next thing was the return of No.
6 lorry and the clean-shaven driver. You remember it had started out
loaded at about eleven. It came back empty shortly after the other, say
about a quarter to three. It didn't stop and there was no change made
with its number. Then there was another pause. At half past three your
friend came out again with another load. This time he was driving No.
1, and I waited to see him stop and change it. But he didn't do either.
Sailed away with the number remaining 1. Queer, isn't it?"

Merriman nodded and Hilliard resumed.

"I stayed where I was, still watching, but I saw no more lorries. But I
saw Miss Coburn pass about ten minutes later--at least I presume it was
Miss Coburn. She was dressed in brown, and was walking smartly along the
lane towards the road. In about an hour she passed back. Then about five
minutes past five some workmen went by--evidently the day ends at five.
I waited until the coast was clear, then went down to the lane and had a
look round where the lorry had stopped and saw it was a double bend and
therefore the most hidden point. I walked back through the wood to the
bridge, picked up my taxi and got back here about half past seven."

There was silence for some minutes after Hilliard ceased speaking, then
Merriman asked:

"How long did you say those lorries were away unloading?"

"About four hours."

"That would have given them time to unload in Bordeaux?"

"Yes; an hour and a half, the same out, and an hour in the city. Yes,
that part of it is evidently right enough."

Again silence reigned, and again Merriman broke it with a question.

"You have no theory yourself?"

"Absolutely none."

"Do you think