The thing that keeps life keen is that you can never figure out what’s ahead.

There’s always a surprise around the corner. The thing changes on you, to use an expression of the vernacular. One begins in an English drawing-room and winds up on the Gobi Desert. You never know where the road’s going. Take it in big things, or take it in the trivialities of life—it’s the same system.

But I am not going to lecture on philosophy; I am going to cite a case—a case that had an immense surprise in it to me, and a series of events that started out in one direction and concluded in another. I saw them start simply enough, but they “changed on me,” to keep our colloquialism.

I had just come down from Bar Harbor. I had an artificial diamond made in Germany, and I was looking for Walker. Walker is chief of the United States Secret Service, and he knows more about artificial stones than any other man in America, unless it is Bartoldi.

Gems are a fad with Walker, and a profession with Bartoldi.

I do not know which of these motive impulses moves a man to the higher efficiency. The keen man with the fad gets to be an expert, and the necessities of trade makes the other one. Anyway, I wanted to show my diamond to both of them.

I found Walker in the Forty-seventh National Bank on lower Fifth Avenue. He waved a recognition and went on with what he was saying to the cashier behind the grill:

“There was no robbery; that’s what puzzles me. How did they get the thing? It’s lucky the bank discovered that it was missing almost immediately and sent out the word. The package had just come in, and was lying on a shelf under the bookkeeper’s desk.... But how did they get it?”

And so I found Walker.

Nobody would ever have taken Walker for the chief of the government Secret Service. In appearance he was the last person any one would have picked out for a secret agent.