"What on earth are you doing?" muttered Captain Harren, twisting his short mustache in perplexity.
"I am copying what I see through this magnifying glass written on the window pane in the photograph," said the Tracer calmly. "Can't you see those marks?"
"I—I do now; I never noticed them before particularly—only that there were scratches there."
When at length the Tracer had finished his work he sat, chin on hand, examining it in silence. Presently he turned toward Harren, smiling.
"Well?" inquired the younger man impatiently; "do those scratches representing Solomon's Seal mean anything?"
"It's the strangest cipher I ever encountered," said Mr. Keen—"the strangest I ever heard of. I have seen hundreds of ciphers—hundreds—secret codes of the State Department, secret military codes, elaborate Oriental ciphers, symbols used in commercial transactions, symbols used by criminals and every species of malefactor. And every one of them can be solved with time and patience and a little knowledge of the subject. But this"—he sat looking at it with eyes half closed—"this is too simple."
"Simple!"
"Very. It's so simple that it's baffling."
"Do you mean to say you are going to be able to find a meaning in squares and crosses?"