Lawrence gave the order to halt, and told Harry and another of the company to dismount and steal carefully through the woods, and see what they could discover. They did so, and soon came to a stream. The bridge that spanned it had, to Harry's astonishment, been only partially destroyed; it could easily be crossed. This looked suspicious. The other bank of the stream was covered by a thick growth of bushes. Their leaves rustled gently as they were touched by the breeze, and that was all. There was no sign of life. Bruno, as he looked across the stream, gave a low, menacing growl, and his eyes shone like two coals of fire. The road, after crossing the bridge, was narrow, and ran between two hills, both thickly wooded. "There's something over there in the bushes," whispered Harry. "We'd better go back and report to the Captain." They did so. "We'll wait until some of the command come up," said Lawrence. They had not long to wait. A company of Merrill Horse that was leading the advance came in sight. To the Captain in command Lawrence explained his fear of an ambuscade in front. The company was halted, the men dismounted, and a skirmish line formed. The men were instructed to work their way carefully to the bank of the stream, but not to show themselves. "I see nothing alarming over there," said the Captain of the company, as he swept the other side of the stream with his glass. "There is something," said Lawrence. "I have just seen a bush tremble more than if stirred by the wind. That half-destroyed bridge is but a trap." By this time more of the troop had come up, and had been halted. With them were a couple of pieces of artillery. "We are losing valuable time," grumbled the Captain. "We'd better ride on, before McNeil gives us thunder." "Not if I can prevent it," said Lawrence. "Bring up that artillery." The two pieces were brought as close to the river as they could without being seen. The horses were then unhitched, and the pieces run forward by hand, so that a few yards more would bring them into view, and in a position where they could sweep the bushes on both sides of the road across the stream. "Load with canister," ordered Lawrence. "When all is ready, I will order a volley fired across the river into the bushes. Wait for the returning volley, for I am sure it will come; then run up your pieces and sweep both sides of the road." The skirmishers crept carefully forward, and at the word poured a volley into the bushes across the stream. The effect was electrical. The bushes seemed to burst into smoke and flame, and then came a crashing volley in return. Quick as thought, the two cannon were run forward and a storm of canister swept the bushes. There were howls of rage, curses and groans, and the guerrillas were in wild flight. With cheers the men ran back, mounted their horses and started in pursuit, thinking the time had come for them to annihilate Porter and his gang.