In June, 1917, some of General Pershing's first troops sailed from New York, in number about 15,000 men, in 13 transports. On that very day a Spanish firm in the city filed a cable to Spain, saying:-- "Quote 13 millers at 15 per cent." The censor's suspicious mind, always on the alert for something unusual, saw that this message could easily be a code, which would mean to the man receiving it, "Sailed, 13 transports with 15,000 troops." It was too probable to be an accident, thought the censor, and he decided to watch Mendez & Co. A few days later two more transports sailed, and Mendez filed three more cables, each containing the number 2, with other figures. The censor promptly put the detectives on the trail. The merciless grasp of the Secret Service, which always "gets" its man, then settled about Mendez. The Spaniard could make no move, day or night, that was not immediately known to the Service. In the dead of an autumn night, two agents opened the door of Mendez' office with a master key, and searched his desk. One man ran over all the papers, reading them rapidly in a low voice, while his companion, an expert stenographer, took down the words with lightning speed. This done, they placed a dictagraph in the inner office, working quickly and well. With a final glance around, they left, having completed the work in a remarkably short time. The next day Mendez' telephone was tapped. Then his secretary left, and the new one he hired was a Secret Service agent. The Spaniard never guessed it, for the secretary brought the most trustworthy references. Every time Mendez held a meeting of his group of German agents and talked of how to send information to Germany, the secretary heard all they said, and at once reported it to his chief. Every time Mendez telephoned, a Secret Service agent listened to what he said. Every time he had a conference in his office, if the secretary by chance was not there, the dictagraph made a record of the conversation, and the Service knew about it. Naturally such careful watching won in the end. Mendez, who had caught the German habit of believing that no one was so clever as himself, did not dream of the net that was being woven around him, and went on filing his cable messages which, of course, were not sent. All the information obtained by the Secret Service was sifted, arranged, and confirmed, and Mendez was arrested. With his departure, his whole following was helpless, and settled back to swear at the United States for its tyranny. The patient Secret Service had scored again.