As Lieutenant-Colonel Gordon was suffering from an attack of chills and fever, Major Lyon was placed in command of the regiment. He was instructed to move almost directly southward, by the way of a small village called Crespin, the name of which has since been changed. The road was a fair one, and ten o'clock in the morning saw the Riverlawns on the move. It was not intended that the round-up should last more than four or five days, and the cavalry went in the lightest possible marching order. Less than ten miles had been covered when the scouts in advance, under Captain Ripley of the eighth company, sent word back that a small detachment of Confederates were in advance, driving about thirty horses southward just as hard as they could. Besides the horses, they had three Union prisoners, one of whom wore the uniform of a captain of artillery. "Three prisoners and thirty horses," mused Deck. "We must stop them, by all means." Without delay he sent for Majors Truman and Belthorpe and gave the necessary orders, and soon the Riverlawns were making the best possible speed over the torn-up pike. A distance of two miles was covered in less than twenty minutes, when another report came in that astonished Deck beyond measure. The report was as follows:-- "Confederate force, horses, and prisoners have utterly disappeared. No buildings or woods for them to hide in. Cannot guess what has become of them. Looks as if the earth had swallowed them up, but the quicksands are not quite bad enough for that. Will keep our eyes wide open, but that is all we can do." Without delay Deck, accompanied by Major Belthorpe, rode forward to investigate. CHAPTER XIX IN WHICH THE RIVERLAWNS ARE CAUGHT IN A TRAP To have a body of the enemy disappear utterly from view when there were no hills or woods in which they might hide, was a new experience to Major Lyon, and it was small wonder, therefore, that his brow contracted into a frown as he urged Ceph ahead at topmost speed. "What do you make of this, Tom?" he questioned, of the major of the second battalion. "Hang me if I know what to make," was the answer. "Captain Ripley must be losing his eyesight if he can't keep forty or fifty men and nearly a hundred horses in sight." "Then his whole command must be losing their eyesight, for the enemy is gone, and nobody can even guess where to." "We'll solve the mystery somehow, Deck. But we ought to beware that we don't fall into some trap." It took but a few minutes to reach Captain Ripley's advance guard, consisting of one-third of the eighth company. The captain himself had the blankest look on his face Deck had ever beheld. "It gets me, Major; never heard of such a thing in all my born days," declared the captain. "We saw them as plain as day, riding behind yonder hedge. They didn't come out at the other end, and so I and three of the others climbed into the trees, only to find the vicinity of the brush deserted. Reckon the earth has swallowed 'em up."