"Of course," murmured the Special Messenger, gently tapping her riding skirt with her whip. "Because," continued the Colonel, "headquarters is stripping this depot of troops. The Bucktails go to-day; Casson's New York brigade and Darrel's cavalry left yesterday. What remains is a mighty small garrison for a big supply depot--eleven hundred effectives, and they may take some of them at any moment. You see the danger?" "Yes, I do." "I've protested; I've pointed out the risk we run; I sent my third messenger to headquarters this afternoon. Of course, they don't intend to leave this depot unguarded--probably they'll send the Vermont troops from the North this week--but between the departure of Casson's column and the theoretical arrival of reenforcements from Preston, we'd be in a bad way if Stuart should raid us in force. And with this irritating and constant leaking out of information I'm horribly afraid he'll strike us as soon as the Bucktails entrain." "Why don't you hold the Pennsylvania infantry until we can find out where the trouble lies?" asked the girl, raising her dark eyes to the nervous young Colonel. "I haven't the authority; I've asked for it twice. Orders stand; the Bucktails are going, and I'm worried to death." He shoved his empty pipe into his mouth and bit viciously at the stem. "Then," she said, "if I'm to do anything I'd better hurry, hadn't I?" The young officer's face grew grimmer. "Certainly; but I've been a month at it and I'm no wiser. Of course I know you are very celebrated, ma'am; but, really, _do_ you think it likely that you can pick out this hidden mischief-maker before he sends word to Stuart to-night of our deplorable condition?" "How long have I?" "About a day." "When do the Bucktails go?" "At nine to-night." "Who knows it?" "Who doesn't? I can't move a regiment and its baggage in a day, can I? I've given them twenty-four hours to break camp and entrain." "Does the train master know which troops are going?" "He has orders to hold three trains, steam up, night and day." "I see," she murmured, strapping her soft riding hat more securely to her hair with the elastic band. Her eyes had been wandering restlessly around the tent as though searching for something which she could not find. "Have you a good map of the district?" she asked. He went to his military chest, opened it, and produced a map. For a while, both hands on the table, she leaned above the map studying the environment. "And Stuart? You say he's roaming around somewhere in touch with Sandy River?" she asked, pointing with a pencil to that metropolis on the map. "The Lord knows where _he_ is!" muttered the Colonel. "He may be a hundred miles south now, and in my back yard to-morrow by breakfast time. But when he's watching us he's usually near Sandy River." "I see. And these"--drawing her pencil in a wavering line--"are your outposts? I mean those pickets nearest Sandy River." "They are. Those are rifle pits."