ive me lessons on the guitar. He
didn't mind if he did, and we got quite friendly. I spent several evenings
in his cave, where one night I heard a dog howling, as if it was mighty
sick, behind a red curtain."

"That red curtain!" I exclaimed. "I shouldn't be where I am now, or have a
scar on the back of my head, if I'd looked behind it."

"By Jove! Well, I got some idea of that sort. Castello said the dog
belonged to a gentleman in Granada, who lived all alone in the Albaicin,
and kept this beast as a watch-dog; but he was afraid it was going mad,
and told Castello to shoot it. However, it was a valuable animal, and
Castello was undertaking to cure it for his own benefit. Already it was
better, and the owner talked of buying it back if it recovered. The old
gentleman was coming up to see the dog that very evening, perhaps,
Castello said; and being evidently proud of a respectable acquaintance, he
went on talking about him, I encouraging him all I could, because any
friend of his might prove interesting to me.

"The minute I heard the chap was a kind of herb doctor, and sometimes
treated grand people, I nearly jumped off my seat; for you know why
Carmona was supposed to come to Granada?"

I nodded.

"Well, Castello was in with this doctor in a way, for he was engaged by
him to fetch herbs and flowers from the mountains--like the Manzanilla, for
instance, which only begins to grow at an elevation of twelve thousand
feet. Castello believed that the old fellow could make poisons too, as
well as antidotes; and said I to myself, 'Maybe that little dagger in the
cathedral was specially prepared, eh?' Which would account for Carmona
hurrying off to Granada after it had found the wrong billet.

"Anyhow, I said I'd like to see the dog, so I was taken behind the red
curtain into Mr. Castello's bedroom, and on a shelf lay a revolver which
might have been twin to the one you bought in Madrid."

"It was still more nearly related," said I.

"Well, I thought so, but wasn't sure enough to call on the police. I went
away when I'd said nice things about the sick dog; but I didn't go far. I
hung around till Castello's visitor had been and gone, and then followed
him to the door of this house. Such a mild, intelligent looking,
well-dressed old gentleman, the herb doctor was; but I guess I needn't
describe him to you!

"Next day I bought some things at a baker's not far from here, and
buttered up the shopkeeper, saying his store wa