While the rain all the day before had brought gloom to the hearts of Sherburne and his men it had filled his with joy, as he thought of the innumerable brooks and creeks that were pouring their swollen waters into the Potomac, already swollen too. He meant now to follow Sherburne's force, see what plan it would attempt, what point, perhaps, it would select for the bridge, and then bring the Union brigades in haste to defeat it. It is said that men often feel when they are watched, although the watcher is invisible, but it was not so in Sherburne's case. He did not in the least suspect the presence of Shepard or of any foe, and the spy, after he had seen all he wished, withdrew, with the same stealth that had marked his coming. An hour after midnight all were awakened and they rode away. The next day they reached the Potomac near Williamsport, where their pontoon bridge had been destroyed, and looked upon the wide stream of the Potomac, far too deep for fording. "If General Lee is attacked on the banks of this river by greatly superior forces," said Sherburne, "he'll have no time to build bridges. If we didn't happen to be victorious our forces would have to scatter into the mountains, where they could be hunted down, man by man." "But such a thing as that is unthinkable, sir," said Harry. "We may not win always, but here in the East we never lose. Remember Antietam and the river at our back." "Right you are, Harry," said Sherburne more cheerfully. "The general will get us out of this, and here is where we must cross. The river may run down enough in two or three days to permit of fording. God grant that it will!" "And so say I!" repeated Harry with emphasis. "I mean to hold this place for our army," continued Sherburne. "A reserved seat, so to speak." "Yes, that's it. We must keep the country cleared until our main force comes up. It shouldn't be difficult. I haven't heard of any considerable body of Union troops between us and the river." They made camp rapidly in a strong position, built their fires for cooking, set their horses to grazing and awaited what would come. It was a dry, clear night, and Harry, who had no duties, save to ride with a message at the vital moment, looked at once for his friends, the Invincibles. St. Clair met him and held up a warning hand, while Happy touched his lip with his finger. Before the double injunction of silence and caution, Harry whispered: "What's happened?" "A tragedy," replied St. Clair. "And a victory, too," said Happy Tom. "I don't understand," said Harry. "Then look and you will," said St. Clair.