On the desk of the private office lay two objects — a key and an envelope.

Mann sat before the desk. He opened the envelope and extracted a folded paper. He began to read, and with reading came understanding.

WHILE Rutledge Mann was gaining his first insight into the methods of the mysterious man who had befriended him, another man who had business in New York was opening a letter at his breakfast table in his home in New Jersey. This was Cliff Marsland, a veteran of the World War, who had done his part in a recent campaign against the New York racketeers.

The letter which Cliff read was written in blue ink, and its words formed a private code which only he understood. Scarcely had he finished reading, when the writing began to disappear. The paper was blank when Cliff dropped it on the breakfast table.

“Darling,” he said to his wife, “I think it would be a good idea for you to take that Florida trip with your father. So plan to leave with him tonight. I have work to do that may take me away for a while.”

Meanwhile, in the club car of the Eastern Limited, a young man known as Harry Vincent, was smoking a cigar and staring meditatively at the passing scenery. Harry had terminated his vacation early that morning. He had left his parents’ home in the little town of Colon, and was riding east from Michigan, in response to an oddly worded telegram which he had received the night before — a message which he alone could understand.

And at precisely the same moment, Clyde Burke was hanging up the receiver of a telephone at the Classic office. He had just been listening to the words of a quiet voice which had spoken to him over the wire.

“Burbank!” Clyde Burke said in an undertone. “Burbank, the trusted agent of The Shadow! Burbank is on the job, and I have received instructions!”

Five men had received their orders. Simultaneously, The Shadow, the unknown master of mystery, had summoned his underlings, each to await his commands. While the police, with hundreds at their disposal, were blindly seeking to learn the identity of Double Z, The Shadow had prepared for battle with the newcomer in the world of crime.

CHAPTER VII. THE SHADOW AT WORK