Perhaps I should never have been able to answer it at all but for one of the photographs which, as I thought, though lying loose by itself, formed part of the same series.  It represented the end of a hundred-yard race, with the winners coming in at the tape by a pavilion with a flag-staff.  On the staff a big flag was flying loosely in the wind.  The folds hid half of the words on its centre from sight.  But this much at least I could read: 

“Er...Om..OY...LETI...UB.”

I gazed at them long and earnestly.  After a minute or two of thought, I made out the last two words.  The inscription must surely be Something-or-other Athletic Club.

But what was “Er... om.. oy...”?  That question staggered me.  Gazing harder at it than ever, I could come to no conclusion.  It was the name of a place, no doubt:  but what place, I knew not.

“Er”?  No, “Ber”:  just a suspicion of a B came round the corner of a fold.  If B was the first letter, I might possibly identify it.

I took the photograph down to Aunt Emma, without telling her what I meant.  She couldn’t bear to think I was ever engaged in thinking of my First State at all.

“Can you read the inscription on that flag, auntie?” I asked.  “It’s an old photograph I picked up in the attic at The Grange, and I’d like to know, if I could, at what place it was taken.”

Aunt Emma gazed at it long and earnestly.  Her colour never changed.  Then she shook her head quietly.

“I don’t know the place,” she said; “and I don’t know the name.  I can’t quite make it out.  That’s E, and R, and O. You see, the letters in between might be almost anything.”

I wasn’t going to be put off, however, with the port thus in sight.  One fact was almost certain.  Wherever that pavilion might be, the murderer was there on the day unknown when those photo-graphs were taken.  And whatever that day might be, my father and the murderer were there together.  That brought the two into connection, and brought me one step nearer a solution than ever the police had been; for hitherto no one had even pretended to have the slightest clue to the personality of the man who jumped out of the window.

I went into the library and took down the big atlas.  Opening the map of England and Wales, I began a hopeless search, county by county, from Northumberland downward, for any town or village that would fit these mysterious letters.  It was a wild and foolish idea.  In the first place not a quarter of the villages were marked in the map; and in the second place, my brain soon got muddled and dazed with trying to fit in the names with the letters on the flag.  Two hours had passed away, and I’d only got as far down as Lancashire and Durham.  And, most probably even so, I would never come upon it.

Then suddenly, a bright idea broke on my brain at once.  The Index!  The Index!  Presumably, as no fold seemed to obscure the first words, the name began with what looked like a B. That was always something.