e
brightest one of all was that we were being damn fools, and working at
this thing from the wrong end altogether."

"Well, that's helpful."

"Of course it's very hampering being a detective, when you don't know
anything about detecting, and when nobody knows that you're doing
detection, and you can't have people up to cross-examine them, and you
have neither the energy nor the means to make proper inquiries; and,
in short, when you're doing the whole thing in a thoroughly amateur,
haphazard way."

"For amateurs I don't think we're doing at all badly," protested Bill.

"No; not for amateurs. But if we had been professionals, I believe we
should have gone at it from the other end. The Robert end. We've been
wondering about Mark and Cayley all the time. Now let's wonder about
Robert for a bit."

"We know so little about him."

"Well, let's see what we do know. First of all, then, we know vaguely
that he was a bad lot--the sort of brother who is hushed up in front of
other people."

"Yes."

"We know that he announced his approaching arrival to Mark in a rather
unpleasant letter, which I have in my pocket."

"Yes."

"And then we know rather a curious thing. We know that Mark told you all
that this black sheep was coming. Now, why did he tell you?"

Bill was thoughtful for a moment.

"I suppose," he said slowly, "that he knew we were bound to see him, and
thought that the best way was to be quite frank about him."

"But were you bound to see him? You were all away playing golf."

"We were bound to see him if he stayed in the house that night."

"Very well, then. That's one thing we've discovered. Mark knew that
Robert was staying in the house that night. Or shall we put it this
way--he knew that there was no chance of getting Robert out of the house
at once."

Bill looked at his friend eagerly.

"Go on," he said. "This is getting interesting."

"He also knew something else," went on Antony. "He knew that Robert was
bound to betray his real character to you as soon as you met him.
He couldn't pass him off on you as just a travelled brother from the
Dominions, with perhaps a bit of an accent; he had to tell you at once,
because you were bound to find out, that Robert was a wastrel."

"Yes. That's sound enough."

"Well, now, doesn't it strike you that Mark made up his mind about all
that rather quickly?"

"How do you mean?"

"He got this letter at breakfast. He read it; and directly he had read
it