Dick was a fine swimmer, he had a good stout plank, and the waters of the river were warm. He felt that the chief dangers were passed, and that the muddy Mississippi would now bear him safely to the blockading fleet below. He gave the plank another shove, sending it farther out into the stream, and then raised himself up until his elbows rested upon it. He could thus float gently with a little propulsion from his legs to the place where he wanted to go.  
He saw lights along the bluff and the bar below, and then, with a sudden shoot of alarm he noticed a dim shadow move slowly from the shore. It was a long boat, holding a dozen rowers, and several men armed with rifles, and it was coming toward him. He did not know whether it was merely an ordinary patrol, or whether they had seen the darker blot on the stream that he and the plank made, but in any event the result would be the same.
 
He slipped his arm off the plank and sank in the stream to the chin. Then, propelling it gently and without any splashing of the water, he continued to move down the stream. He was hopeful that the riflemen would mistake him and his plank for one of those stumps or logs which the Mississippi carries so often on its bosom.
 
The head of the boat turned from him a little, and he felt sure now that he would drift away unnoticed, but one of the soldiers suddenly raised his rifle and fired. Dick heard the bullet clip the water close beside him, and he swam as hard as he could for a few moments. Then he settled again into quiet, as he saw the boat was not coming toward him. Doubtless the man had merely fired the shot to satisfy himself that it was really a log, and if Dick allowed it to float naturally he would be convinced.
 
It was a tremendous trial of nerves to run the gantlet in this way, but as it was that or nothing he exerted all his will upon his body, and let himself float slowly, sunk again to the mouth and with his head thrown back, so it would present only a few inches above the surface.
 
The boat turned, and seemed once upon the point of coming toward him. He could hear the creaking of the oars and the men talking, but they turned again suddenly and rowed up the stream. Again, his fate had hung on a chance impulse. He drifted slowly on until the town and the bluffs sank in the darkness. Then he drew himself upon his plank and swam, doubling his speed. He knew that some of the union gunboats lay not far below, and, when he rounded a curve, he saw a light in the stream, but near the shore.
 
He approached cautiously, knowing that the men on the vessel would be on guard against secret attack, and presently he discerned the outlines of a sidewheel steamer, converted into a warship and bearing guns. He dropped down by the side of his plank until he was quite close, and then, raising himself upon it again, he shouted with all his voice: “Ship ahoy!”
 
He did not know whether that was the customary method of hailing on the Mississippi, but it was a memory from his nautical reading, and so he shouted a second and yet a third time at the top of his voice: “Ship ahoy!” Figures bearing rifles appeared at the side, and a rough voice demanded in language highly unparliamentary who was there and what he, she or it wanted.
 
Dick was in a genial mood. He had escaped with an ease that surprised him, and the warmth of the water in which he was immersed had saved him from cramp or chill. The spirit of recklessness seized him again. He threw himself astride his plank, and called out:
 
“A detachment of the army of the United States escaped from captivity in Vicksburg, and wishing to rejoin it. It's infantry, not marines, and it needs land.”
 
“Then advance infantry and give the countersign.”
 
“Grant and Victory,” replied Dick in a loud, clear voice.
 
A laugh came from the steamer, and the rough voice said again:
 
“Let the detachment advance again, and holding up its hands, show itself.”
 
Dick paddled closer and, steadying himself as well as he could, threw up his hands. The light of a ship's lantern was thrown directly on his face, and the same voice ordered men to take a small boat and get him.
 
When Dick stepped upon the deck of the steamer, water streaming from his clothes, several men looked at him curiously. One in a dingy blue uniform he believed to be the owner of the rough voice. But his face was not rough.
 
“Who are you?” asked the man.
 
“Lieutenant Richard Mason of Colonel Winchester's regiment in the army of General Grant, sent several days ago with a message to the fleet, but driven by Confederate scouts and skirmishers into Vicksburg, where he lay hidden, seeking a chance of escape.”
 
“And he found it to-night, coming down the river like a big catfish.”
 
“He did, sir. He could find no other way, and he arrived on the useful board which is now floating away on the current.”
 
“What proof have you that you are what you say.”
 
“That I saw you before you saw me and hailed you.”
 
“It's not enough.”
 
“Then here is the message that I was to have delivered to the commander of the fleet. It's pretty wet, but I think you can make it out.”
 
He drew the dispatch from the inside pocket of his waistcoat. It was soaked through, but when they turned the ship's lantern upon it the captain could make out its tenor and the names. Doubt could exist no longer and he clapped his hands heartily upon the lad's shoulder.
 
“Come into the cabin and have something to eat and dry clothes,” he said. “This is the converted steamer union, and I'm its commander, Captain William Hays. I judge that you've had an extraordinary time.”
 
“I have, captain, and the hardest of it all was when I saw our army repulsed to-day.”
 
“It was bad and the wounded are still lying on the field, but it doesn't mean that Vicksburg will have a single moment of rest. Listen to that, will you, lieutenant?”
 
The far boom of a cannon came, and Dick knew that its shell would break over the unhappy town. But he had grown so used to the cannonade that it made little impression upon him, and, shrugging his shoulders, he descended the gangway with the captain.
 
Clothing that would fit him well enough was found, and once more he was dry and warm. Hot coffee and good food were brought him, and while he ate and drank Captain Hays asked him many questions. What was the rebel strength in Vicksburg? Were they exultant over their victory of the day? Did they think they could hold out? What food supply did they have?
 
Dick answered all the questions openly and frankly as far as he could. He really knew little or nothing about those of importance, and, as for himself, he merely said that he had hid in a cave, many of which had been dug in Vicksburg. He did not mention Colonel Woodville or his daughter.
 
“Now,” said Captain Hays, when he finished his supper, “you can have a bunk. Yes, lieutenant, you must take it. I could put you ashore to-night, but it's not worth while. Get a good night's sleep, and we'll see to-morrow.”
 
Dick knew that he was right, and, quelling his impatience, he lay down in one of the bunks and slept until morning.
 
Then, after a solid breakfast, he went ashore with the good wishes of Captain Hays, and, a few hours later, he was with the union army and his own regiment. Again he was welcomed as one dead and his own heart was full of rejoicing because all of his friends were alive. Warner alone had been wounded, a bullet cutting into his shoulder, but not hurting him much. He wore a bandage, his face had a becoming pallor, and Pennington charged that he was making the most of it.
 
“But it was an awful day,” said Warner, “and there's a lot of gloom in the camp. Still, we're not moving away and the reinforcements are coming.”
 
Dick explained to Colonel Winchester why he had failed in his mission, and the colonel promised to report in turn to the commander that the hand of God had intervened. Dick's conscience was now at rest, and he resumed at once his duties with the regiment.
 
Many days passed. While Grant did not make any other attack upon Vicksburg his circle of steel grew tighter, and the rain of shells and bombs upon the devoted town never ceased. Reinforcements poured forward. His army rose to nearly eighty thousand men, and Johnston, hovering near, gathering together what men he could, did not dare to strike. Dick was reminded more than once of Caesar's famous siege of Alesia, about which he had read not so long ago in Dr. Russell's academy at Pendleton.
 
There were long, long days of intrenching, skirmishing and idleness. May turned into June, and still the steel coil enclosed Vicksburg. Here the union men were hopeful, but the news from the East was bad. Not much filtered through, and none of it struck a happy note. Lee, with his invincible legions, was still sweeping northward. Doubtless the Confederate hosts now trod the soil of a free State, and Dick and his comrades feared in their very souls that Lee was marching to another great victory.
 
“I wish I could hear from Harry Kenton,” said Dick to Warner. “I'd like to know whether he passed through Chancellorsville safely.”
 
“Don't you worry about him,” said Warner. “That rebel cousin of yours has luck. He also has skill. Let x equal luck and y skill. Now x plus y equals the combination of luck and skill, which is safety. That proves to me mathematically that he is unharmed and that he is riding northward—to defeat, I hope.”
 
“We've got to win here,” said Dick. “If we don't, I'm thinking the cause of the union will be more than doubtful. We don't seem to have the generals in the East that we have in the West. Our leaders hang on here and they don't overestimate the enemy.”
 
“That's so,” said Pennington. “Now, I wonder what 'Pap' Thomas is doing.”
 
“He's somewhere in Tennessee, I suppose, watching Bragg,” said Dick. “That's a man I like, and, I think, after this affair here is over, we may go back to his command. If we do succeed in taking Vicksburg, it seems likely to me that the heavy fighting will be up there in Tennessee, where Bragg's army is.”
 
“Do you know if your uncle, Colonel Kenton, is in Vicksburg?”
 
“I don't think so. In fact, I'm sure he isn't. His regiment is with Bragg. Well, George, what does your algebra tell us?”
 
Warner had taken out his little volume again and was studying it intently. But he raised his head long enough to reply.
 
“I have just achieved the solution of a very important mathematical problem,” he answered in precise tones. “An army of about thirty-five thousand men occupies a town located on a river. It is besieged by another army of about seventy-five thousand men flushed with victory. The besiegers occupy the river with a strong fleet. They are also led by a general who has shown skill and extraordinary tenacity, while the commander of the besieged has not shown much of either quality and must feel great discouragement.”
 
“B............