Every attache of the German embassy is to be guarded with extreme care, day and night. Reports are to be made through the usual channels and, in the event that something unusual is observed, Divisional Headquarters is to be notified instantly, the information being transmitted to Washington before any final action is taken. This last clause, of course, was inserted to prevent some hot-headed operative from going off half-cocked and thus spoiling the State Department's plans. As long as Albert and his associates were merely "guarded" they couldn't enter any formal complaint. But, given half a chance, they would have gotten on their official dignity and demanded that the espionage cease. From the State Department's point of view it was an excellent rule, but Gene Barlow and the other Service men assigned to follow Albert couldn't see it in that light. "What's the idea, anyhow?" Gene growled one night as his pet taxicab dashed down Massachusetts Avenue in the wake of the big touring car that was carrying the German attache to the Union Station. "Here we have to be on the job at all hours, just to watch this Dutchman and see what he does. And," with a note of contempt, "he never does anything worth reporting. Sees half a dozen people, lunches at the German-American Club, drops in at two or three offices downtown, and then back here again. If they'd only let us waylay him and get hold of that black bag that he always carts around there'd be nothing to it. Some day I'm going to do that little thing, just to see what happens." But Barlow took it out in threats. Secret Service men find pleasure in stating what they are going to do "some day"--but the quality of implicit obedience has been drilled into them too thoroughly for them to forget it, which is possibly the reason why they take such a sheer and genuine delight in going ahead when the restrictions are finally lifted. It was in New York, more than two years after the war had commenced, that Barlow got his first opportunity to "see what would happen." In the meantime, he had been assigned to half a dozen other cases, but always returned to the shadowing of Doctor Albert because he was the one man who had been eminently successful in that work. The German had an almost uncanny habit of throwing his pursuers off the trail whenever he wanted to and in spite of the efforts of the cleverest men in the Service had disappeared from time to time. The resumption of unrestricted submarine warfare and the delicacy of the diplomatic situation which ensued made it imperative that the "man with the saber scar," as Doctor Albert was known, be kept constantly under surveillance. "Stick to him, Gene, and don't bother about reporting until you are certain that he will stay put long enough for you to phone," were the instructions that Barlow received. "The doctor must be watched every moment that he's away from the Embassy and it's up to you to do it."