They did not have enough men. They did not have enough aeroplanes. No sooner had that thought crossed his mind than a U.S. fighting scout zoomed past the waddling barrel. Morrell waved, though the pilot was gone by then. He almost wished it had been a Confederate aeroplane; he longed to try out the light machine gun as an antiaircraft weapon and give some Reb a nasty surprise.

The Confederate States did not have enough barrels, either, nor fully understand what to do with the ones they had. Every so often, a few of their rhomboids would come forward to challenge the U.S. machines. Individually, theirs were about as good as the one Morrell commanded. But what he and Ned Sherrard and General Custer had grasped and the Confederates had not was that, with barrels, the whole was greater than the sum of its parts. A mass of them all striking together could do things the same number could not do if committed piecemeal.

A shell whine in the air sent Morrell ducking back inside his steel turtle’s shell. Even as he ducked, a shell burst close to the barrel. Fragments hissed past him and clattered off its plating. None bit his soft, tender, vulnerable flesh, though.

More shells burst close by. A battery of C.S. three-inchers was doing its best to knock out his barrel and any others close by. Except at very short range, field guns hit barrels only by luck, but the hail of splinters from the barrage forced Morrell to stay inside for a while.

It was like dying and going to hell, except a little hotter and a little stickier. July in Tennessee was not the ideal weather in which to fight in a barrel. The ideal weather, for men if not for engines, would have been January in Labrador. The barrel generated plenty of heat on its own. When its shell trapped still more…Morrell was coming to understand how a rib roast felt in the oven.

And the rest of the crew suffered worse than he did. When he stood up, he got a breeze in his face: a hot, muggy breeze, but a breeze even so. They got only the whispers of air that sneaked in through louvered vision slits and the mountings of the cannon and machine guns. The engineers, down below Morrell in the bowels of the barrel, got no air at all, only stinking fumes from the twin truck engines that kept the traveling fortress traveling.

Morrell stood up again. Shells were still falling, but not so close. There was Nolensville, only a few hundred yards ahead. Infantrymen and machine-gun crews were firing from the houses and from barricades in the street, as they did in every little town. As Morrell watched, a shell from the cannon of another U.S. barrel sent chunks of a barricade flying in all directions. A moment later, that barrel started to burn. Soldiers leaped from it. Morrell hoped they got out all right. He sprayed a few rounds in front of them to make the defenders keep their heads down.

Infantrymen in green-gray and barrels converged on Nolensville. U.S. aeroplanes strafed the Confederates in the town from just above chimney height. Morrell did not order his barrel into Nolensville, where it might easily come to grief moving along any of the narrow, winding streets. He poured machine-gun fire and cannon shells onto the Rebels from just outside, where the barrel could move as freely as…a barrel could move.

Some of the defenders died in Nolensville. Some, seeing they could not hold the town, broke and ran. Morrell’s barrel rumbled past Nolensville. He took potshots at fleeing men in butternut, some white, some colored. Some of them, probably, had been brave for a long time. Under endless hammering, though, even the hardest broke in time.

Another Confederate came out from behind a large, dun-colored rock. Morrell swung the light machine gun toward him. He was on the point of opening fire when he saw the man was holding a flag of truce.

Bullets from one of the barrel’s hull machine guns stitched the ground near the Confederate officer’s feet. He stood still and let the flag be seen. The machine gun stopped firing. All over the field, firing slowed to a spatter and stopped.

Morrell ducked down into the cupola. Halt, he signaled urgently. Then, like a jack-in-the-box, he popped up again. Even before the barrel had fully stopped, he scrambled down off it and ran toward the Confederate with the white flag. “Sir, I am Colonel Irving Morrell, U.S. Army. How may I be of service to you?”

Courteously, the Rebel, an older man, returned the salute. The three stars on each side of his stand collar showed his rank matched Morrell’s. “Harley Landis,” he said. He said nothing after that for close to half a minute; Morrell saw tears shine in his eyes. Then, gathering himself, he resumed: “Colonel, I-I am ordered to seek from the U.S. Army the terms you will require for a cease-fire, our own forces having proved unable to offer effectual resistance any longer.”

Joy blazed in Morrell. To let his opposite number see it would have been an insult. Sticking to business would not. “How long a cease-fire do you request, sir, and on how broad a front?”

“A cease-fire of indefinite duration, along all the front now being defended by the Army of Kentucky,” Landis answered. Again, he seemed to have trouble finding words. At last, he did: “I hope you will forgive me, sir, but I find this duty particularly difficult, as I was born and reared outside Louisville.”

“You have my sympathies, for whatever they may be worth to you,” Morrell said formally. “You must understand, of course, that I lack the authority to grant a cease-fire of any such scope. I will pass you back to First Army headquarters, which will be in touch with our War Department. I can undertake to say that troops under my command will observe the cease-fire for so long as they are not fired upon, and so long as they do not discover C.S. troops improving their positions or reinforcing-or, of course, unless I am ordered to resume combat.”

“That is acceptable,” Colonel Landis said.

“A question, if I may,” Morrell said, and the Confederate officer nodded. Morrell asked, “Are the Confederate States requesting a cease-fire along the whole front, from Virginia to Sonora?”

“As I understand it, no, not at the present time,” Harley Landis replied.

Morrell frowned. “I hope you see that the United States may find it difficult to cease fighting along one part of the front while continuing in another?”

“Way I learned it, fighting in the War of Secession went on a while longer out here than it did back East, on account of the United States kept trying to hold on to Kentucky,” Landis said.

That was true. Whether it made a binding precedent was another question. Morrell shrugged. “Again, that’s not for me to say, sir. Let’s head back toward Nashville till I can flag down a motorcar and put you in it. The sooner the fighting does stop, the better for both our countries.”

“Yes, sir. That’s a fact.” As Landis stalked past the barrel from which Morrell had emerged, he glowered in its direction. “You Yankees hadn’t built these damn things in carload lots, we’d have whipped you again.”

“I don’t know,” Morrell said. “We’d stopped you before we began using them. Breaking your lines would have been a lot harder without them, though; I will say that.” Landis didn’t answer. He kept on glaring. But he kept on walking, too, north and west toward Nashville and First Army headquarters. The white flag in his hand fluttered in the breeze.

Every soldier in green-gray who saw the Confederate officer inside U.S. lines with a flag of truce stared and stared, then burst into cheers. Off in the distance, gunfire still rattled here and there. It fell silent, one pocket after another. The Rebels had to be sending more men forward under flag of truce to let U.S. forces know they were seeking a cease-fire.

Before Morrell spotted a motorcar, he found something even better: a mobile field-telephone station, the men still laying down wire after them as their wagon tried to keep up with the advance. “Can you put me through to Nashville?” he demanded of them. They nodded, eyes wide with wonder as they too gaped at Harley Landis and the flag he bore. Morrell said, “Then do it.”