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.

What should she do?  Vividly there flashed into her mind her chief’s parting words.

“Watch everything,” he had charged her.  “Remember everything, report everything.  No detail is too unimportant.  If you see one of the Hoffs leave the house, don’t merely report to me that the old man or the young man left the house about three o’clock.  That won’t do at all.  I want to know the exact time.  Was it six minutes after three or eleven minutes after three?  I must know what direction he went, if he was alone, how long he was absent, where he went, what he did, to whom he talked.  Here in my office I take your reports, Carter’s reports, a dozen other reports, and study them together.  Things that in themselves seem trifling, unimportant, of no value, coupled with other seemingly unimportant trifles sometimes develop most important evidence.”

To prove his point he had told her of the seemingly innocent wireless message that an operator, listening in, had picked up, at a time when Germans were still permitted to use the wireless station on Long Island for commercial messages to the Fatherland.  On the face of it, it was the mere announcement of the death of a relative with a few details.  But a little later the same operator caught the same message coming from another part of the country, with the details slightly different, and still later another message of the same purport.  Evidently, by comparing the messages, the United States authorities had been able to work out a code.