Thirteen! Fateful number! Was this a warning to me to leave the whole thing alone? Very possibly. Anyway, except as a warning, it seemed to be singularly useless. I declined to believe that any conspirator would take that way of writing thirteen in real life. If he meant thirteen, he would write thirteen. “13”⁠—like that.

There was a space between the one and the two. I accordingly subtracted twenty-two from a hundred and seventy-one. The result was a hundred and fifty-nine. I did it again and made it a hundred and forty-nine. These arithmetical exercises were doubtless excellent practice, but as regarded the solution of the mystery, they seemed totally ineffectual. I left arithmetic alone, not attempting fancy division or multiplication, and went on to the words.

“Kilmorden Castle.” That was something definite. A place. Probably the cradle of an aristocratic family. (Missing heir? Claimant to title?) Or possibly a picturesque ruin. (Buried treasure?)