“When you ’phoned me he was there in our apartment, he and a navy lieutenant, Mr. Kramer.”

Attentively he listened as she told of the ruse by which she had inveigled them into coming to luncheon, reminding him that it was the same naval officer that he himself had seen in close conversation with Hoff at the Ritz the day before.  He nodded his head in a satisfied way.

“They are together too much to be up to any good,” he commented.  “Tell me the rest.  What made you so rattled when I ’phoned you?”

He listened intently as she told of finding young Hoff standing right behind her as she had inadvertently mentioned aloud “the fifth book.”

“Do you suppose,” she questioned anxiously, “that he overheard me and understood what we were talking about?  He left right away after that.  I do hope I didn’t betray the fact that they are being watched.”

“We can’t tell yet,” said Carter.  “The precautions they take and the roundabout methods they have of communicating with each other show that all Germany’s spies constantly act as if they knew they were under surveillance.  In fact, I suppose every German in this country, whether he is a spy or not, can’t help but notice that his neighbors are watching him—­and well they might.”

“I don’t see why,” cried Jane, “Mr. Fleck did not have old Mr. Hoff locked up right away.  He could not do any more damage then, or be sending any more messages about our transports.”

“That wouldn’t have done the least bit of good,” said Carter decisively.  “Watching our transports sail and spreading the news is only one of many of their activities.  Somewhere in this country there is a master-council of German plotters, directing the secret movements of many hundreds, perhaps many thousands of spies and secret agents.  They have their work well mapped out.  They have men fomenting strikes in the government shipyards and stirring up all kinds of labor troubles.  Others are busy making bombs and contriving diabolical methods of crippling the machinery in munition plants.  A flourishing trade in false passports is being carried on, enabling their spies to travel back and forth across the Atlantic in the guise of American business men, ambulance drivers, Red Cross workers and what not.  Still others of their agents are detailed to arrange for the shipping of the supplies Germany needs to neutral countries.  By watching shipping closely they gather information, too, that is of value to the U-boat commanders.  Every time there is any sort of activity against the draft, or peace meetings, or Irish agitation, we find traces of German handiwork.  We have dismantled and sealed up every wireless plant we could find in America except those under direct government control, yet we are positive that every day wireless messages go from this country somewhere—­perhaps to Mexico or South America, and from there are relayed to Germany, probably by way of Spain.  Think of