"Watkins? Yes, I do. He once called on my father, about the same time that Mr. Styles called last."
"Do you know why he called?"
"I do not. I thought it was about a patent. I learned that Mr. Watkins worked for the United States government and I thought it was for the patent office."
"Then that is all, Miss Langmore." The detective arose and held out his hand. "Now take good care of yourself and do not worry. Matters are bound to come out right in the end."
"But how can they be better for me?" Margaret's face took on its worried look again. "They have proved that I am guilty."
"You are not guilty," said Adam Adams firmly and looking her squarely in the eyes. "You are not guilty. I say so, and I know. Do not worry. Rest quietly, and soon everything shall be made plain to you." And then before she could answer he was gone. She sank back among the pillows, closed her eyes and heaved a sigh.
"It cannot be!" she murmured. "It is too late! I am guilty! I am guilty!"
CHAPTER XXII
AN UNDERGROUND MYSTERY
Late that afternoon a burly negro, plainly dressed and wearing a slouch hat, made his way along the river road in the direction of the old mill. He kept as much as possible in the shade of the bushes and trees and when close to the mill sank low in the tall grass, that he might not be seen by anyone who was passing.