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.
So it went. For every German spy or would-be spy in America, there was an agent of the Secret Service, equally resourceful, and more likely to succeed, because, no matter how clumsy his adversary seemed, he never made the mistake of underrating him. "Stupid Yankees," von Papen had called us, while he went about his plotting with child-like faith in his skill at hiding. "Stupid Germans," the Secret Service might have retorted, as it skillfully uncovered all his plotting and sent him back to his Kaiser, where his stupidity was more appreciated.
But it took many months of patient, unceasing work, and far the greatest part of it was dull, hard, steady grind. Rarely was there any excitement for the industrious government agents, and more rarely was there any glory, for the work had to be kept secret. Trailing, watching, studying, thinking, always putting two and two together and often finding that they made five instead of four; through day and night, through sun and storm, the officers whose duty it was to catch the spy before he could harm America worked steadily on.
That is why America won at home just as she won abroad. Had not the silent army in the United States fought so unceasingly and so skillfully, the army in France would have been paralyzed. When you think of the Great Victory, remember those quiet, unknown men and women at home who did so much to help win it, and give full credit to the Secret Service.
ROGER WILLIAM RIIS.