“There’s a leak somewhere,” insisted the angry officer; “it smells to Heaven, but I can’t locate it. Somewhere there’s a direct, intelligent and sinister underground communication between Osage Court House and Jeb Stuart at Sandy River—or wherever he is. And what I want you to do is to locate that leak and plug it.”

“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 reënforcements 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?”