"I can't believe it," cried Jane, "our own American officers traitors!"

"Undoubtedly some of them are," said Mr. Fleck regretfully. "The German efficiency, for years looking forward to this war, carefully built up a far-reaching spy system. Years ago, long before the war was thought of--or at least before we in this country thought of it--many secret agents of Wilhelmstrasse were deliberately planted here. Many of them have been residents here for years, masking their real occupation by engaging in business, utilizing their time as they waited for the war to come by gathering for Germany all of our trade and commercial secrets.

Some of these spies have even become naturalized, and they and their sons pass for good American citizens. In some cases they have even Americanized their names. Insidiously and persistently they have worked their way into places, sometimes into high places in our chemical plants, our steel factories, yes, even into high places in our army and navy and into governmental positions where they can gather information first-hand. In no other country has it been so easy for them, because of this one fact: so large a proportion of Uncle Sam's population is of German birth or parentage. Why here in New York City alone there are more than three-quarters of a million persons, either German-born themselves or born of German parents. Many of them, the vast majority of them, probably, are loyal to America, but think how the plenitude of German names makes it easy for spies to get into our army and navy.

Besides that, they employ evil men of other nationalities as spies, the criminal riffraff,--Danes, Swedes, Spaniards, Italians, Swiss and even South Americans,--all of whom are free to go and come as they choose in this country."

"I never realized before," said Jane, "how many Germans there were all about us."

"In an effort to locate this particular band of naval spies," continued Mr. Fleck, "we have combed the apartment houses and residences along the Drive. Three places in particular are under suspicion. The apartment of the Hoffs is one of these places. They moved in there thirty days after this country went to war. Ordinarily, where the occupants of an apartment are under suspicion, we take the superintendent of the building partly into our confidence and plant operatives in the house, or else we hire an apartment in the same building. In this case neither course is practicable. The superintendent of your building is a German-American and we dare not trust him, and there is no vacant apartment that we can rent. We have been watching the Hoffs from the outside as best we could. Carter, who has had charge of the shadowing, accidentally happened to overhear you give your address. He had procured a list of the tenants and remembered the location of your apartment. It struck him at once that you would be a valuable ally if you would consent to work with us."