"That the police were after them, and detectives had communicated with the federal authorities at Washington," she went on. "The writer was clearing for Denver and he advised Mrs. Atterbury to 'tail' or trace the movements of 'The Comet,' that she was 'yellow' or crooked."
"Well done!" The detective thumped the desk in his enthusiasm. "There's a place here for you if ever you want to take it, Miss Westcote! That letter was written by 'Red' Rathbone."
"What does he look like?" the girl asked suddenly.
"Tall and shambling, bright red hair," McCormick replied with an inquiring look. "No eyebrows or lashes; they were burned off in a prison fire the last time he was sent up. Got a curious way of carrying his head on one side——"
"Then I know him, too!" she exclaimed. "His soubriquet 'Red' reminded me. He must have been the manservant who opened Mrs. Atterbury's door to me on my first visit! I wonder I did not think of him when I read the cipher letters."
"What were they?"
"I have them here." She produced two papers from her handbag and placed them before him. "The first is a copy of a letter which Mrs. Atterbury dictated to me."
"'My dear Shirley,'" read McCormick. "'Your letter received. Send me ten of the thousand circulars quoting sheep prices for March. Home market good this week for forty or fifty and even more points rise if my brokers handled the situation properly.' H—m! I don't quite get it."
"You will if you read every third word, eliminating the two between." The girl rose and bent over the desk. "You see? It really means: 'Received ten thousand sheep. March good for fifty more if handled properly.'
"I was convinced that this could only be read aright by choosing certain combinations of words, and I tried all that I could think of, backward and forward, until I came upon the key."