She returned to Miss Clay’s side and gazed hard at the vehicles.

Theodora said, “They’ve got a little armor plating, but nothing that could withstand anything like the antiaircraft cannons on our engine.”

“They look fast, though. Maybe they think that if they can catch up fast enough, we won’t have much time to fire at them.”

“Then they’re idiots. Jesus, they’re coming right for us!”

But Mercy said, “No, not right for us.” The formation of machines was forking, spreading out and lining up. “Look what they’re doing. They’re going for the engine and the caboose.”

“Whatever for?”

“Well, they know we’ve got passengers aboard,” Mercy pointed out. “And they don’t give a shit about the passengers. They want something else. Something at the front, or the rear.” She felt like she was stating the obvious, and the longer she watched, the more obvious it became—the machines were deliberately parting to ignore the middle cars.

“You say that like they’re reasonable human beings,” Miss Clay spit.

“They’re every bit as reasonable as the boys aboard this train,” she said stubbornly. “Thinking less of them than that’ll get you killed.”

Theodora looked like she would’ve loved to argue, but she heard her aunt bullying and bossing out in the aisle and changed her mind, or her tactic, at least. She said, “Leaving room for error, if all the passengers holed up in the middle cars, they might be safest.”

“You might be right.”

The forward door burst open and Cyrus Berry came squeezing through it, followed by Inspector Galeano and Pierce Tankersly, then Claghorn Myer and Fenwick Durboraw, two other enlisted men whom Mercy had seen coming and going along the train.

Mercy said, “But not yet—we’ve got to let the soldiers sort themselves out.” She cried, “Mr. Tankersly!” and summoned him over.

In a few fast words, she explained her guess and Miss Clay’s idea. He nodded. “That’s a good plan. I’m going to put you in charge of it.”

“What?”

“We’ve been split into squadrons fore and aft, and we’re migrating that way now. Do you have a watch?”

“Not on me,” she confessed.

“Does anybody have a watch?” he asked the room. When he was greeted only with mumbles and the frantic mechanizations of people building fortresses out of luggage, Mercy stopped him.

She asked, “How long do you need to get into place?”

“Five minutes,” he said. “Give us five minutes. Can you guess that pretty good?”

“Yes,” she said, then turned him around and gave him a shove. “Now get moving!”

The whole clot of officials went struggling through the narrow aisle to the back door. Once they were through it, Mercy and Theodora considered the plan.

“There are seven passenger cars,” Mercy counted out. “If everyone from the first and seventh can squeeze into the middle five, that’ll leave the first and last as buffers and won’t crush everyone too badly in the rest.”

Miss Clay said, “Yes. And we’ll probably even be able to keep the aisles clear, once everyone’s settled. Do you want to go up to the first car, or back to the last one?”

“Um . . . I don’t know. It doesn’t matter.”

Theodora Clay made a sound of sublime exasperation and held out a coin as if to flip it. She said, “Last car’s closest to where we are, so that’ll be easiest. On the count of three, heads or tails . . .”

“Tails,” Mercy said, and when heads flashed up, she added, “That’s fine. I’ll work my way up front. You work your way to the rear, and we’ll meet back in the middle.”

Miss Clay nodded as crisply as any soldier ever clicked to attention.

Mercy grabbed her satchel and threw off her cloak to make her movements easier—never mind the cold between the cars; she could stand it. She checked her guns, and the two women walked into the aisle, narrowly dodging a second wave of uniformed men brandishing weapons. Then they turned different directions, and ran.

Mercy backtracked the way she’d just come, urging people in the central cars into makeshift shelters and reassuring the hysterical that a plan was in place, though she went out of her way to keep from explaining that it was a feeble plan, consisting mostly of the order to “Move!” But a plan kept things from going straight to hell, and the soldiers appeared to appreciate it, going so far as to assist where possible as they polarized themselves forward and aft, setting up defensive positions and barricades in the places where the Confederate raiders seemed most likely to attack.

She met Captain MacGruder back in the first passenger car. When she’d finished herding its occupants into the second car, the captain reached for Mercy’s arm and lured her back into the first one, where his soldiers were holing up and readying themselves. He stood there, struggling to ask her something, and not knowing how to phrase it.

“Can I help you, Captain?” she tried to prompt him.

He said, “It’s only . . . I hope we’re doing the right thing, leaving the passenger cars unguarded.”

She said, “So do I.”

“It’s placing a great deal of faith in our enemy . . . ,” he observed.

Mercy agreed, “Perhaps.” Then she looked about. Seeing no truly unoccupied corners, she led him over to an abandoned compartment and pretended they’d achieved a fragile modicum of privacy. “Sir, let me ask you something.”

“By all means.”

“What do they want?”

He said, “I beg your pardon?”

“I may not be an officer, but I’m not an idiot, either. And this train, this trip . . . it’s a big fat pile of horse pucky, and it smells like it, too.”

“I have no idea what you’re talking about,” he said, with just enough hesitation to make Mercy quite certain he was lying.

Exasperated, she said, “Look at those machines out there. They’ll be on us at any minute. I’ve never seen anything like them, have you?”

“No, I haven’t. But why would you—?”

“They’re expensive, I bet. Probably made in Texas like all the best war toys, and then shipped up here on one of the Republican rail lines that meets up at the Utah pass. That’s not a cheap thing to do.”

“Madam, I assure you this is purely a civilian mission—”

“Oh, and I’m your mother!” she almost yelled at him. Again she pointed out the window, to a place where the vehicles were shambling at breakneck speed over the low grassy nubs on the prairie. “Look at them. They know. They know the passengers are a bluff. They’re aiming for the engine and the caboose, or the after-​caboose. And I want you to tell me, Captain MacGruder . . . why?”

The captain stiffened, and said slowly, “As a civilian, none of this is your concern.”

“As a woman stuck on this goddamn train with you and your boys, and someone else’s boys getting ready to open fire on us, it sure as hell is my concern.”

But then a whirring noise up front declared that the Dreadnought’s defense systems were winding up, threading strands and coils of bullets up to the Gatling-​copies mounted on the engine’s sides. Mercy said, “Captain!” She wasn’t sure what she’d follow it with, a plea for information or a demand for instructions, but nothing had time to come.

With a jolt that kicked the first couple of passenger cars and made them sway, the Dreadnought opened fire, spraying a line of bullets across the sand-​colored earth and blasting pits in wavy rows. The mechanized three-​wheelers were barely within range, and they dodged, ducking and bucking left to right and back again—unexpectedly stable for such spindly looking creations. In a moment, all of them righted themselves and struck a forward course once more.

“Get back to your car and stay down,” the captain commanded, at the exact moment the Rebel craft fired back.

A hail of bullets smashed through the windows that hadn’t been opened, sending sprays of glass exploding through the narrow compartment. Everyone ducked and shook their heads, casting shards out of their hair and off their shoulders. Mercy crouched in the compartment, the captain crouching with her.

He said again, “Go, for God’s sake!”

More fire from the Dreadnought made the cars rock and shake, giving the towed compartments a centrifugal snap every time the larger guns were fired. Mercy retreated as ordered—stopping at the doors and holding her breath, waiting, trying to calculate the incalculable. There was no way to time her steps to a steady roll of the train, because she had no way of knowing when it would fire; so she breathed deeply, yanked at the door, flung herself into the next car, and hoped for the best.

By the time she’d made it back to the third car, one car shy of her goal, a man caught up to her from the first compartment, where half the soldiers were busy fending off the Rebs.

The soldier called out, “Mrs. Lynch!”

When she turned around, he did not wait for confirmation, just wheezed, “Can you come back to the front car? We’ve got some men hurt.”

“Already? But I just left!” she exclaimed, then waved her hands as if to dismiss her own reaction. “Never mind, I’m coming. I’m right behind you.”

The sun was more set than not, and its grim yellow glow was the only thing lighting the train. The porters had snuffed the gas lamps and then, no doubt, holed up someplace sensible. Moving up and down the aisles was like crashing through someone else’s nightmare, and it was an increasingly dark nightmare, with exponentially more terrors, as the light faded and the confusion mounted.

Just when Mercy thought she couldn’t possibly find her way through one more car, she reached her goal, seizing the last frigid handle and clutching it, in order to move herself across the wind-​torn space.

“I’m here,” she announced with a gasp. “Who needs me?”