I was struggling through the porridge of a late breakfast when Geoffrey strolled in. I gave him a cigarette and went on eating. He wandered round the room in a restless sort of way and I could see he was thinking out an ending for his latest lie. I was well away with the toast and marmalade when he started.

"You know that dog of mine, Rupert? Well, yesterday—"

I let him talk; I could afford to be generous this morning. He had hashed up an old story of how this regrettable hound of his had saved the household from being burnt to death in their beds the night before.

I did not listen very attentively, but I gathered it had smelt smoke, and, going into the dining-room, had found the place on fire and had promptly gone round to the police-station.

When he had finished I got up and lit a pipe.

"Not one of your best, Geoffrey, I'm afraid—not so good, for instance, as that one about the coastguard and the sea-gulls; still, I could see you were trying. Now I'll tell you about Leopold's extraordinary acuteness yesterday afternoon.

"We—he and I—were out on the parade, taking a little gentle after-luncheon exercise, when I saw him suddenly stop and start to point at a man sitting on one of the benches a hundred yards in front of us; but not in his usual rigid fashion; he seemed to be puzzled and uncertain whether, after all, he wasn't making a mistake."

Here Geoffrey was unable to contain himself, as I knew he would be.

"Lord! That chestnut! You went and asked the man his name and he told you that it was Partridge."

"No," I said, "you are wrong, Geoffrey; his name, on inquiry, proved to be Quail. But that was only half the problem solved. Why, I thought, should Leopold have been so puzzled? And then an idea struck me. I went back to the man on the bench and, with renewed apologies, asked him if he would mind telling me how he spelt his name. He put his hand into his pocket and produced a card. On it was engraved, 'J.M. Quayle.' Then I understood. It was the spelling that puzzled Leopold."