“Tell me.”

“A—­a dream?  Do you wish to know what I dreamed?”

“Yes—­if it was a dream.”

“It was.  I was asleep on the deck of the Mindinao, dead tired after a fruitless hike.  I dreamed she came toward me through a young woodland all lighted by the sun, and in her hands she held masses of that wild flower we call Solomon’s Seal.  And she said—­in the voice I know must be like hers:  ’If you could only read!  If you would only understand the message I send you!  It is everywhere on earth for you to read, if you only would!’

“I said:  ‘Is the message in the seal?  Is that the key to it?’

“She nodded, laughing, burying her face in the flowers, and said: 

“’Perhaps I can write it more plainly for you some day; I will try very, very hard.’

“And after that she went away—­not swiftly—­for I saw her at moments far away in the woods; but I must have confused her with the glimmering shafts of sunlight, and in a little while the woodland grew dark and I woke with the racket of a Colt’s automatic in my ears.”

He passed his sun-bronzed hand over his face, hesitated, then leaned over the photograph once more, which the Tracer was studying intently through the magnifying glass.

“There is something on that window in the photograph which I’m going to copy,” he said.  “Please shove a pad and pencil toward me.”

Still examining the photograph through the glass which he held in his right hand, Mr. Keen picked up the pencil and, feeling for the pad, began very slowly to form the following series of symbols: 

[Illustration:  Cryptographic symbols]

“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?”