Variations of that stunt occurred time after time. Even the detailing of two men to follow him failed in its purpose, for the Austrian would enter a big office building, leap into an express elevator just as it was about to ascend, slip the operator a dollar to stop at one of the lower floors, and be lost for the day or until some one picked him up by accident.
So Cap Kenney called in four of his best men and told them that it was essential that Weimar be watched.
"Two of you," he directed, "stick with him all the time. Suppose you locate him the first thing in the morning at his house on Twenty-fourth Street, for example. You, Cottrell, station yourself two blocks up the street. Gary, you go the same distance down. Then, no matter which way he starts he'll have one of you in front of him and one behind. The man in front will have to use his wits to guess which way he intends to go and to beat him to it. If he boards a car, the man in front can pick him up with the certainty that the other will cover the trail in the rear. In that way you ought to be able to find out where he is going and, possibly, what he is doing there."
The scheme, thanks to the quick thinking of the men assigned to the job, worked splendidly for months—at least it worked in so far as keeping a watch on Weimar was concerned. But that was all. In the summer of 1915 the government knew precisely where Weimar had been for the past six months, with whom he had talked, and so on—but the kernel of the nut was missing. There wasn't the least clue to what he had talked about and what deviltry he had planned!
Without that information, all the dope the government had was about as useful as a movie to a blind man.
Washington was so certain that Weimar had the key to a number of very important developments—among them the first attempt to blow up the Welland Canal—that the chief of the Secret Service made a special trip to New York to talk to Kenney.
"Isn't it possible," he suggested, "to plant your men close enough to Weimar to find out, for example, what he talks about over the phone?"
Kenney smiled, grimly.
"Chief," he said, "that's been done. We've tapped every phone that Weimar's likely to use in the neighborhood of his house and every time he talks from a public station one of our men cuts in from near-by—by an arrangement with Central—and gets every word. But that bird is too wary to be caught with chaff of that kind. He's evidently worked out a verbal code of some kind that changes every day. He tells the man at the other end, for example, to be at the drug store on the corner of Seventy-third and Broadway at three o'clock to-morrow afternoon and wait for a phone call in the name of Williams. Our man is always at the place at the appointed hour, but no call ever arrives. 'Seventy-third and Broadway' very evidently means some other address, but it's useless to try and guess which one. You'd have to have a man at every pay station in town to follow that lead."
"How about overhearing his directions to the men he meets in the open?"