possibilities of Oakes's own mental instability. While Moore was deep in thought, he was suddenly interrupted by the bell, and the receipt of a note which had been delivered by the postman. He glanced at the postmark, and saw that it was from Station O and was mailed at 4:30. Somehow, he felt an instinctive dread of its contents. Of course, he as yet had no adequate cause for misgivings; but there was that in the subject of which he had been thinking that seemed to forecast evil and dread. His mind was in a state of unrest at the very thought of the possibilities. He tore the letter open, and read: CONTENTS [Pg 53] "Dear Dr. Moore: You may not deem it wise to pay attention to an anonymous communication, but let me assure you that, if you value a life, you will pay attention in this case. Dear Dr. Moore [Pg 53] [Pg 53] "It has come within my province to know that a great tragedy may be averted by you. "Some short while ago a man, tall, straight as an arrow, and with blue eyes, went to the town of Mona and stopped at the Mansion. There he came near being murdered, and if he ever goes back, I personally know that he will be killed in short order. "His business was said to be that of an agent for the owners. I saw him in New York several years ago, and he was pointed out to me as a celebrated detective, but I cannot remember his name, or that of the person who informed me. "At Mona he was known by another name. I cannot go there, however, or learn any more particulars. The reason I address this to you is that I know that you are acquainted with him, as years ago I used to see him often in your company. "Now please communicate with this man; you are the only thread that I have to his identity. "Reach him, if possible, at once. Warn him. Tell him to turn backāto abandon his quest, for death to him is the only alternative.