"Elkin's mixture was not 'as before.' It was fortified," grinned
Furneaux. "That's the exact increase of nicotine. By the way, I have
a sample. We can take care of him on that charge, without a shadow
of doubt."

Winter blew softly on the back of his friend's head.

"You're thorough, Charles, thorough!" he murmured. "It's a treat to work
with you when you get really busy."

Furneaux ran his thumb across the end of several leaves.

"I can tell you now," he said, "that there's nothing of real value in the
earlier notes. So far as I can judge, they refer either to a sort of
settlement with his wife or chance phrases used by Doris Martin which
might imply that she was heart whole and fancy free. There's not a bally
word dealing with the murder, or that can be twisted into the vaguest
allusion to it. But here's a plan and section which have a sort of
significance. I've seen the place, so recognized it, or thought I did. We
must check it, of course. Here you are! You know the footbridge across
the river from Bush Walk?"

"Yes."

"The eastern end is supported on a hollow pier of masonry, in which one
might tog up unseen. These drawings would be useful as an _Aide
Memoire_ on a dark night. A false step, with the river in flood, might
be awkward."

"What's that on the opposite page?"