Subway passengers sitting opposite Jane Strong as she rode up-town from Mr. Fleck's office, if they observed her at all--and most of them did--saw only a slim, good-looking young girl, dressed in a chic tailormade suit, crowned with a dashing Paris hat tilted at the proper angle to display best the sheen of her black, black hair, which after the prevailing fashion was pulled forward becomingly over her ears.

Outwardly Jane was unchanged, but within her nerves were all atingle at the thought of the tremendous and fascinating responsibility so unexpectedly thrust upon her. Her mind, too, was aflame with patriotic ardor, but coupled with these new sensations was a persisting sense of dread, an intangible, unforgettable feeling of horror that kept cropping up every time her fingers touched the little metal disk in her purse.

The man who had carried it yesterday, the other "K-19" who had undertaken to shadow those people next door, now lay dead with a bullet through his heart. Was there, she wondered, a similar peril confronting her? Would her life be in danger, too? Was that the reason Mr. Fleck had told her of her predecessor's fate--to warn her how desperate were the men against whom she was to match her wits? Yet no sense of fear that projected itself into her busy brain as she cogitated over the task before her held her back. If anything she was rather thrilled at the prospect of meeting actual danger. What bothered her most was how she could best go about aiding Mr. Fleck and his men in their work.

Her opportunity came far more quickly than she had anticipated. She had gotten off the train at the 96th Street station, purposing to walk the twenty odd blocks to her home as she pondered over the work that lay ahead of her. Busy with a horde of struggling new thoughts she proceeded along Broadway, for once in her life unheeding the rich gowns and feminine dainties so alluringly displayed in the shop windows. Suddenly she pulled herself together with a start. Directly ahead of her, plodding along in the same direction, was a figure that from behind seemed strangely familiar. She quickened her step until she caught up sufficiently with the man ahead to get a good glimpse of his side face.

Nervously she caught her breath. Without any doubt it was the gray Van Dyke beard of old Otto Hoff.

Where was he going? What was he doing? She paused and looked behind her, scanning the pavement on both sides of the street. She was half-hoping that she would discover Carter or some of his men shadowing their quarry, but her hope was vain. There was no one in the block at the moment but herself and Mr. Hoff. If Fleck's men had been watching his movements, the old man certainly seemed to have eluded them.