“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.