"Perhaps none. But I was trying to narrow down the possible actors. If you on your part have kept the knowledge of these letters to yourself inviolately, then the information about them must have been given out by Fullerton if at all. Do you know anyone to whom he would be likely to confide such a matter,--any confidant or chum?"
She shook her head helplessly. "I know nothing of his friends. My impression is that he had very few. He was a strange, solitary, secret man."
"And yet it must be clear that either he wrote this himself, or it was written on his private paper in his handwriting, by someone who had intimate knowledge of his affairs,--not only of the fact that he had those letters of yours, but of the threat which he held over you in regard to them. Now if he wrote it himself, why wasn't it mailed until yesterday? And who did mail it yesterday, anyhow? If someone was in his confidence and is trying to play upon your fears, we must find out who it is. May I take this letter with me?"
"I don't want to ever see it again."
"And if you receive any other letters or anything comes up in any way bearing on this, will you let me know at once? I am going to try to find out about his office help. And I will leave this letter open to the sunlight for a day. If it was written yesterday, the ink will show a change by to-morrow. If written a week ago, it probably will not. As soon as I learn anything that will interest you, I will let you know."
But as he was departing she detained him, some unspoken anxiety visibly struggling with her habit of reserve.
"You spoke, when you were here before, of the possibility of my being called as a witness. If that should happen, would I have to tell about--this?"
"I do not see how it could come up, unless they could connect Lawrence with it in some way. Of course if they were trying to establish motive,--some reason for Lawrence's quarrel with Fullerton,--it might seem to have a bearing. But you never discussed Fullerton with Lawrence."
"No," she said, but her look was still troubled. "If you are questioned," he said quietly, "you will not have to testify except so far as you have positive knowledge. You will not have to give your thoughts or theories or guesses."
"I see," she murmured, dropping her strange, guarded eyes.