No sooner had Agatha Ronald determined to enter upon a career of very dangerous service to her cause and country, than she set herself diligently to the work of perfecting plans which were at first vague and undefined. It was no part of her purpose to fail if by any forethought and thoroughness of preparation she might avert the danger of failure. She determined to do nothing until every point and possibility, so far as conditions could be foreseen, should be considered and provided for. First of all, she entered into perfect confidence with her maid, Martha, telling the trusty negro woman as she meant to tell no other person near her, except her grandfather, precisely what she intended to do, and how. Martha had a shrewd intelligence likely to be useful in emergencies, and her devotion to her mistress was as absolute as that of any devotee to an object of worship. This mistress had been hers to care for by night and by day ever since Agatha had been four years of age. All of loyalty, all of affection, all of self-sacrificing devotion of which the negro character in its best estate is capable, she gave to Agatha, never doubting her due or questioning her right to such service of the heart and soul. She knew no other love than this, no other life than that of unceasing, all-embracing care for her mistress. It was with no shadow of doubt or hesitation, therefore, that Agatha revealed her purposes to Martha, and asked for her aid in carrying them out. And Martha received the somewhat startling confidence as calmly as if her mistress had been telling her of an intended afternoon drive. When matters had settled down into apathetic idleness after the battle of Manassas, Agatha made occasion to visit the army. Officers at Fairfax Court-house had their wives and daughters with them at their headquarters then, and many of these were Agatha's intimates, whom she might visit without formal invitation. At their quarters, she received visits from such of her friends as belonged to the cavalry forces stationed thereabouts. In her intercourse with these, she steadily maintained the innocent little fiction that she was there solely for social purposes, and to see the splendid army that had so recently won an astonishing victory. One day, she learned that the picturesque cavalier, General J. E. B. Stuart, had boldly pushed his outposts to Mason's and Munson's Hills, and established his headquarters under a tree, within easy sight of Washington. She instantly developed an intense desire to visit him there. It happened that she knew Stuart and his family personally, and had often dined in the great cavalry leader's company at her own and other homes. So she said one day, to a young cavalry officer, who was calling upon her: