med only of importance in that it had shown Mark to have adopted
something of a threatening attitude towards his brother. To Antony it
had much more significance. It was the only trustworthy evidence that
Mark had been in the office at all that afternoon.

For who saw Mark go into the office? Only Cayley. And if Cayley had been
hiding the truth about the keys, why should he not be hiding the truth
about Mark's entry into the office? Obviously all Cayley's evidence went
for nothing. Some of it no doubt was true; but he was giving it, both
truth and falsehood, with a purpose. What the purpose was Antony did not
know as yet; to shield Mark, to shield himself, even to betray Mark
it might be any of these. But since his evidence was given for his own
ends, it was impossible that it could be treated as the evidence of
an impartial and trustworthy onlooker. Such, for instance, as Elsie
appeared to be.

Elsie's evidence, however, seemed to settle the point. Mark had gone
into the office to see his brother; Elsie had heard them both talking;
and then Antony and Cayley had found the body of Robert.... and the
Inspector was going to drag the pond.

But certainly Elsie's evidence did not prove anything more than the mere
presence of Mark in the room. "It's my turn now; you wait." That was not
an immediate threat;--it was a threat for the future. If Mark had shot
his brother immediately afterwards it must have been an accident, the
result of a struggle, say, provoked by that "nasty-like" tone of voice.
Nobody would say "You wait" to a man who was just going to be shot. "You
wait" meant "You wait, and see what's going to happen to you later on."
The owner of the Red House had had enough of his brother's sponging,
his brother's blackmail; now it was Mark's turn to get a bit of his own
back. Let Robert just wait a bit, and he would see. The conversation
which Elsie had overheard might have meant something like this. It
couldn't have meant murder. Anyway not murder of Robert by Mark.

"It's a funny business," thought Antony. "The one obvious solution is so
easy and yet so wrong. And I've got a hundred things in my head, and I
can't fit them together. And this afternoon will make a hundred and one.
I mustn't forget this afternoon."

He found Bill in the hall and proposed a stroll. Bill was only too
ready. "Where do you want to go?" he asked.

"I don't mind much. Show me the park."

"Righto."

They walked out together.

"Watson