But the irregulars who had ambushed them, save a few fallen before the bullets, escaped easily in the dense woods, and under cover of the darkness which was now coming down, thick and fast.

A trumpet sounded the recall and the cavalrymen, sore and angry, drew back into the road. They had lost a dozen good men, but Colonel Hertford felt that they could not delay for vengeance. Grant's orders were to come at once; and he intended to obey them.

"I'd wager a year's pay against a Confederate five-dollar note," said Sergeant Whitley to Dick, "that the man who laid that ambush was Slade. He'll keep watch on us all the way to Grant, and he'll tell the Southern leaders everything the general is doing. Oh, he's a good scout and spy."

"He's proved it," said Dick, "and I'd like to get a fair shot at him."

They rode nearly all night and most of the next day, and, in the afternoon, they met other men in blue who told them that a heavy Union force was advancing. They had no doubt now that Grant's great plan was already working and in a short time they reached McPherson, advancing with Logan's division. Hertford reported at once to McPherson, who was glad enough to have his cavalry, and who warmly praised Dick and the sergeant for the dangerous service they had done so well. As it would have been unwise for them to attempt to reach Grant then he kept them with him in the march on Jackson.

Dick slept that night under the stars, but thousands of Union men were around him and he felt neither the weight of responsibility, nor the presence of danger. He missed Warner and Pennington, but he and the sergeant were happy. Beyond a doubt now Grant was going to strike hard, and all the men were full of anticipation and hope. His force in different divisions was advancing on Jackson, leaving Vicksburg behind him and the Southern army under Pemberton on one side.

Dick heard, too, that the redoubtable Joe Johnston was coming to take command of the Southern garrison in Jackson, and a leader less bold than Grant might have shrunk from such a circle of enemies, but Grant's own courage increased the spirit of his men, and they were full of faith.

"I expect they're alarmed in Washington," said the sergeant, as they sat on their blankets. "There ain't any telegraph station nearer than Memphis. They've heard in the capital that the general has begun to move toward Jackson, but they won't know for days what will happen."

"I don't blame the President for being disturbed," said Dick. "After all the army is to serve the nation and fights under the supreme civilian authority. The armies don't govern."

"That's so, but there come times when the general who has to do the fighting can judge best how it ought to be done."

Dick lay down on one blanket and put another over him. It was well into May, which meant hot weather in Mississippi, but, if he could, he always protected himself at night. He was not a vain lad, but he felt proud over his success. Hertford's six hundred horse were a welcome addition to any army.

He lay back soon with a knapsack as a pillow under his head and listened to the noises of the camp, blended now into a rather musical note. Several cooking fires still burned here and there and figures passed before them. Dick observed them sleepily, taking no particular note, until one, small and weazened, came. The figure was about fifty yards away, and there was a Union cap instead of a great flap-brimmed hat on the head, but Dick sprang to his feet at once, snatched a pistol from his belt and rushed toward it.

The evil figure melted away like a shadow, and two astonished soldiers seized the youth, who seemed to be running amuck in the camp, pistol in hand.

"Let go!" exclaimed Dick. "I've seen a man whom I know to be a spy, and a most dangerous one, too."

They could find no trace of Slade. Dick returned crestfallen to his blanket, but he recalled something now definitely and clearly. Slade was the little man whom he had seen carrying the log the morning he left General Grant's camp, on his mission.

The sergeant, who had never stirred from his own blanket, sat up when Dick returned.

"Who was he, Mr. Mason?" he asked.

"Slade himself. He must have seen me jump up, because he vanished like a ghost. But I gained something. I know now that I saw him here in our uniform just before I started to find Colonel Hertford. That was why I was followed."

"The cunning of an Indian. Well, we'll be on the watch for him now, but I imagine he's already on the way to Jackson with the news of our advance and an estimate of our numbers.