"The sentinels are not a hundred yards beyond us," he heard him say. "All three saw them. The ground slopes gradually to the south and west. It's quite open. They crossed the Run down yonder, and rode straight away northward," and the sergeant pointed to a distant ridge. "None of 'em came within range. They didn't seem to think anybody would be out here at all." The staff-officer sat listening quietly and attentively until the sergeant finished. Then he turned to the major. "I chose this ground myself," he said. "The sentries are hidden by bushes from the front, and have a clear view for nearly a mile, by day at least, and looking back you could see the roofs of Centreville on the high ground to the east. I reconnoitred all through here yesterday and came across that bridge about three o'clock. There's a deep wide ditch, marshy in places, wet and miry everywhere for a mile either way, and the banks are steep. Foot troops and cavalry can cross all right, but we've got to keep that bridge for the guns, especially that big thirty-pound Parrott General Hunter's to bring along. I wish we'd been sent out earlier, though of course we might have been seen crossing the open fields. Look!" and Lieutenant Upton led a few paces to the edge of the scattered trees, and there the whole westward firmament was visible, even down to the black lines of the Bull Run Mountains, just setting its own "sentinel stars" for the long night-watch. "I wish so, too," said the major. "Lawton, ride back and guide the column. It may lose the way." Again the lad turned and trotted away, but before he had gone a hundred yards he could see the faint gleam of steel come dancing through the glade, and almost instantly there followed the stern, sharp, low-voiced challenge. "It's Lawton," he answered quickly. "The major feared you might lose the way, and told me to guide you." The men were panting a little now, for Flint was forcing the pace. Something told them there was work ahead. "Know what's up, orderly?" muttered the captain.