“I certainly would,” announced her husband enthusiastically.

“Jane tells me she is writing a novel,” Mrs. Strong continued, “and that’s why she stays in her room so much.  I hope she won’t turn out to be literary.”

“Don’t worry,” advised Mr. Strong.  “With all the men off to war you’ll find young women doing all kinds of funny things to work off their energy.  If a girl can’t be husband-hunting, she’s got to be doing something to keep busy.  There are worse things than trying to write novels.  Jane is all right.  Let her alone.”

So, even though her mother’s suspicions had been aroused, the girl in the next few days managed to spend many hours with her ears glued to the receiver of the dictograph without being discovered.  In the Hoffs’ apartment Dean had succeeded in locating it over the dining-room table, concealed in the chandelier, and in Jane’s room the other end rested in the back of a dresser drawer that she always carefully locked when absent.

The novelty of listening for bits of her neighbors’ conversation quickly wore off.  To sit almost motionless for hours listening, listening intently for every sound, hearing occasional words spoken either in too low tones or too far distant to make them understandable, to record bits of conversation that sounded harmless, yet might have some sinister meaning, became a most laborious task.  Yet persistently Jane stuck at it.  The greater knowledge she gained of the plottings of the German agents, the more important and vital she realized it was for every clue to be diligently followed in the hope that the trail might at last reach the master-spy, whose manifold activities were menacing America.

In general she was disappointed with the results of her listening.  To be sure they had furnished indisputable evidence of something they already had ascertained—­that old Hoff, despite being a naturalized American, still was a devoted adherent of the ruler of Germany.  Nightly as he and his nephew sat down to dinner she could hear his gruff, unpleasant voice ceremoniously proposing always the same toast: 

“Der Kaiser!”

Even when the younger Hoff was dining out, as he sometimes did, Jane could hear the old man giving the toast, presumably with only the old servant for an auditor.  That the woman, too, was a spy, as well as servant, Jane had known since the day on the roof, but so far neither she nor Dean had been able to make anything out of her handkerchief code, though both were sure the messages related to the sailings of transports.

Only once had she heard anything that she deemed really important.  One evening, as uncle and nephew dined, there had been an acrimonious dispute.

“Have you it yet?” the uncle had asked in German.

“Not yet,” Frederic had answered.

His seemingly simple reply for some reason appeared to have stirred the elder man’s wrath.  He broke into a volley of curses and epithets, reproaching his nephew for his delay.  In the rapid medley of oaths and expostulations Jane could distinguish only occasional words—­“afraid”—­“haste”—­“all-highest importance”—­“American swine.”  The younger Hoff had appeared to exercise marvelous self-control.