Lawrence mingled with the crowd, and as he read he felt a bulky envelope thrust in his hand and caught a glimpse of a dusky arm. He glanced at the address and then turned to see who had given it to him, but could not. He glanced at the envelope again. Yes, it was for him. In bold letters was written, "For Captain Lawrence Middleton. Important." The writing was strange to Lawrence, and making his way through the crowd he sought a private place where he could see what had so mysteriously come into his possession. As he read, a look of surprise came over his face, and then his countenance grew stern and grim. Carefully he read the document through from beginning to end. It was signed "By One Who Knows." There was not a mark to tell who was the writer. The writing was strong and bold, and possessed an originality of its own, as if the writer had put much of his own character in it. Lawrence sat and pondered long. He looked the manuscript over and over again to see if he could not discover some private mark, something that would identify the writer, but he found nothing. "Strange," he muttered, "but if Guilford Craig was alive I would swear he was the writer of this. Who else would write me, and me alone, and give such important information? Who else could obtain the information contained in this letter? Yet Guilford is dead. Benton Shelly was seen to shoot him. There were those who saw him lying on the ground, still in death, his bosom drenched in blood. But his body was not found. Guilford, Guilford, are you still alive? But why do I indulge in such vain hope that he is alive? The proof of his death is too plain. This letter must have been written by another, but who? Who? And why send it to me?" The letter was, in fact, a full and complete _exposé_ of the plans of the Confederates. It told of the conception of the plot; who was carrying it out; of the hundreds who had taken the oath of allegiance in order that they might work more securely, and that many had even enlisted in the State militia, so that when the supreme time came they could desert: the time set for the uprising was the last of July or else the first of August, by which time they hoped to have at least forty thousand men enrolled. "Blair and Schofield must see this, and no time lost," said Lawrence to himself as he placed the communication carefully in his pocket. Blair was soon found. After carefully reading the letter he said, "I am not surprised. I warned the Government of the folly of removing so many troops from the State. But who could have written this?" "If Guilford Craig was alive there would be but one answer," replied Lawrence. "As it is, it is a mystery." "Let us see Schofield at once," said Blair. "There should be no time lost."