Muller then hastened to the telegraph office and despatched a lengthy telegram to the postal authorities in Frankfurt am Main.  When the answer came to him next morning, he packed his grip and took the first express train leaving G—.  He first made a short visit, however, to Albert Graumann’s cell in the prison.  Muller was much too kind-hearted not to relieve the anxiety of this man, to whom such mental strain might easily prove fatal.  He told Graumann that he was going in search of evidence which might throw light on the death of Siders, and comforted the prisoner with the assurance that he, Muller, believed Graumann innocent, and believed also that within a day or two he would return to G—­ with proofs that his belief was the right one.

Three days later Muller returned to Grunau and went at once to the Graumann home.  It was quite late when he arrived, but he had already notified Miss Roemer by telegram as to his coming, with a request that she should be ready to see him.  He found her waiting for him, pale and anxious-eyed, when he arrived.  “I have been to Frankfurt am Main,” he said, “and I have seen Mr. Pernburg—­”

“Yes, yes, that is the name; now I remember,” interrupted the girl eagerly.  “That is the name of John’s friend there.”

“I have seen Mr. Pernburg and he gave me this letter.”  Muller laid a thick envelope on the girl’s lap.

She looked down at it, her eyes widening as if she had seen a ghost.  “That—­that is John’s writing,” she exclaimed in a hoarse whisper.  “Where did it come from?”

“Pernburg gave it to me.  The day before his death John Siders sent him this letter, requesting that Pernburg forward it to you before a certain date.  When I explained the circumstances to Mr. Pernburg, he gave me the letter at once.  I feel that this paper holds the clue to the mystery.  Will you open it?”

With trembling hands the girl tore open the envelope.  It enclosed still another sealed envelope, without an address.  But there was a sheet of paper around this letter, on which was written the following: 

My beloved Eleonore: 

Before you read what I have to say to you here I want you to promise me, in memory of our love and by your hope of future salvation, that you will do what I ask you to do.

I ask you to give the enclosed letter, although it is addressed to you, to the Judge who will preside in the trial against Graumann.  The letter is written to you and will be given back to you.  For you, the beloved of my soul, you are the only human being with whom I can still communicate, to whom I can still express my wishes.  But you must not give the letter to the Judge until you have assured yourself that the prosecuting attorney insists upon Graumann’s guilt.  In case he is acquitted, which I do not think probable, then open this letter in the presence of Graumann himself and one or two witnesses.  For I wish Graumann, who is innocent, to be able to prove his innocence.