never letting anything of the personal relation creep in.  That he was college-bred, Jane felt certain.  He spoke both German and French much better than she did.  He occasionally used words that no ordinary chauffeur would be likely to know the meaning of.  Sharing the secret of such a mission as theirs, they quickly found themselves on a friendly basis, yet the girl hesitated whenever her curiosity prompted her to try to find out anything that would reveal his identity.  There was always present the feeling that any exhibition of undue curiosity on her part would be a disappointment to her employer.  The chief disapproved of curiosity except on one subject—­what the Germans were doing.

Many things Jane and her aide learned about the Hoffs in the days following Thomas Dean’s coming, reporting them all as directed.  Of how much or of how little value her discoveries were Jane had no means of knowing.  Chief Fleck seemed satisfied but was always urging her to acquire more information and more details, always details.  Dean, too, had seconded the warning about observing even what seemed to be insignificant trifles.

“Most of the Germans,” he said to her, “you will find are very methodical.  They like to do things according to schedule.  For instance, I learned yesterday that old Hoff and his nephew frequently go off on all-day automobile trips.  They always go on Wednesday.”

“Are they going to-morrow?”

“The presumption is that they will.  They have done so every Wednesday for six weeks.”

“Can’t we follow them in our car?” cried the girl, “and see what they are up to?”

Dean shook his head.

“The Chief is looking out for that.  There is more important work for us to do right here.  I want to try to install a dictograph in their apartment.”

“How exciting.”

“You must find some excuse for me to come up into your apartment and see to it that none of your people are about.”

“That will be easy.  Mother and Aunt will be out all day, and it is cook’s afternoon off.  I can easily send the maids out.”

“But that’s not all.  There is the Hoffs’ servant to be disposed of.”

“I don’t see how I can manage that,” said Jane.  She could think of no possible way of overcoming that difficulty.

“She’s an old German woman—­Lena Kraus,” continued Dean.  “I’ve found out that she always washes on Wednesdays.  When she goes up on the roof in the afternoon to get the clothes will be our time.  It will be your job to see that she stays there until I am through.  It will not take me more than half an hour.”

“But what will I do if she starts to come down?  How will I stop her?”

“You’ll have to use your wits.  Keep her talking as long as you can.  When she starts down come with her.  Press the elevator button four times.  I’ll leave the door of the Hoff apartment open and very likely will hear it in time to get away.”