"Dunno yet. But, say it was done that way, it needn't have been done here. Maybe the murderer put a poisoned mint in the bottle when they were somewhere together."
"How could he?"
"Oh, lots of ways. Say Blair had his coat off, playing golf or billiards, or——"
"He'd carry such a bottle in his waistcoat pocket, I think."
"Well, it's all surmise. The thing to do is to begin from the other end. Who had a motive?"
"That's what I'm trying to trace. Nothing doing as yet. Hello, here's that old letter from Joshua, the guide. Look at it! It is in a small, cramped hand, and you know the one purporting to be from him later was in a big, sprawly hand. Somebody faked that letter!"
"Well, there's something to work on, then."
"But maybe Thorpe did it."
"Not he. Why should he? He had nothing to do with that Labrador trip."
"What was the letter about, the other Joshua letter?"