Theodora Clay gave the lid a supplementary heave. It slid away from the coffin’s top, revealing a body lying within.

Mercy wished with all her might for something like the Texian’s small lighted device, but instead she was forced to wait for her eyes to adjust and for the cold fog to clear enough for her to see inside. As the man’s features came into focus, she gasped, clapping her apron’s corner even more tightly against her face.

Miss Clay did not gasp, but she was clearly intrigued. “He looks just awful,” she observed, though what she expected of a man who’d been dead for some weeks and kept in storage, Mercy wasn’t prepared to guess. “Is that . . .” She pointed at the loll of his neck and the drag of his skin as it began to droop away from his bones. “Is all that normal?”

The nurse’s words were muffled when she replied, “No. No, it’s not normal at all. But I’ve seen it before,” she added.

“Seen what?”

Mercy had had enough. “Close it! Just close the lid and buckle it up again. I don’t need to see any more!”

Theodora Clay frowned, looked back down into the coffin’s interior, and said, “But that’s ridiculous. You haven’t even frisked him for bullet wounds or broken—”

“I said close it!” she nearly shrieked, and toppled backwards away from it.

Perhaps out of surprise, or perhaps only to appease her companion, Miss Clay obliged, drawing the lid back into place and pulling the buckles, seals, and clasps into their original positions. “Well, if you got everything you needed to know from a glance—”

“I did. I saw plenty. That man, he didn’t die in battle.” Mercy turned away and looked longingly at the stack of crates that led to freedom above, and to the light of a dull gray sky. Then she looked back at the crates that took up the places where the coffins had not been placed. She noted the coupler tools, and she picked one of them up.

“Yes,” her companion said, and selected another tool that might be used as a prybar. “We should also examine these before we leave.”

Mercy was already at work on the nearest one. Since it was placed near the square of light from the open hatch above, she was relatively certain that there were no markings present to be deciphered. She pressed her long metal instrument into the most obvious seam and wedged her arm down hard. This gesture was greeted with the splitting sound of nails being drawn unwillingly out of boards, and the puff of crisp, fragile sawdust being disturbed.

Miss Clay was having more difficulty with her own crate, so she abandoned it to see what Mercy had turned up. “What on earth are those things?” she asked.

Mercy reached inside and pulled out a glass mason jar filled with a gritty yellow powder. She shook it and the powder moved like a sludge, as if it had been contaminated by damp. She said, “It must be sap.”

“I’m afraid you must be mistaken. That looks nothing at all like—”

“Not tree sap,” Mercy cut her off. “Sap. It’s . . . it’s a drug that’s becoming real common with men on the front. I’ve heard of it before, and I’ve seen men who abused it bad, but I’ve never seen it. So I might be wrong, but I bet I’m not.”

“Why would you make that bet?”

“Because that man over there—” She used the prybar to point at the coffin. “—he died from this stuff. He’s got all the marks of a man who used it too much, right into the grave.”

“What about the rest of them?”

“What about them?”

“We should see how they died.”

The nurse replaced the jar and plunged her hands down through the sawdust, feeling for anything else. She turned up another jar or two, some labeled samples in scientific tubes, and what looked like the sort of equipment one might use to distill alcohol. She said, “Waste of time. Look at all this equipment.”

“I’m looking at it, but I have no idea what any of it does, or what it is.”

“It looks like a still, sort of. For brewing up moonshine, only not exactly. I think the army’s trying to figure out what makes the drug work, and maybe turn it into a poison, or a weapon, like you said. I think they’ve gotten hold of as much of the yellow sap as they could scare up, and now they’re trying to figure out how they can make a whole passel of it.” The words came tumbling out of her mouth, quivering with her jaw as she did her best not to shiver. “This is all so wrong. We’ve got to get out of here, before we breathe in too much of this junk. Come on, Miss Clay. Let’s go. Me and you, now. We’ve got to leave this alone.”

“Leave it alone?”

“For now, anyway,” she said as she spun around and placed her hands on the large base crate that would lead the way up and out. “There’s nothing we can do for these men, and right now we don’t have proof of anything, just ideas and thoughts. Let’s get out of here so we can think. We can talk about it back in the car, if no one catches us and throws us in jail.”

“Such an optimist you are,” murmured Theodora Clay, who replaced the lid on the crate Mercy had abandoned, then agreeably followed her back up to the ceiling and out onto the car’s roof.

Once they were topside, the two women mashed and heaved the hatch back into its sealed position and began their tricky trip back the way they’d come. Mercy grumbled, “That stink is going to stay with me all day. I bet it’s all in my clothes, and in my hair.”

“Don’t be silly. All this fresh wind will blow it right out of you.”

“I think I’m going to heave my lunch.”

“I pray you’ll restrain yourself,” Theodora Clay said, urging Mercy back down the first ladder, then up the next.

On top of the caboose, they scooted and dragged themselves forward, working against a soft breeze that came at their faces with more snow and tiny flecks of ice. Their silence was complete enough that they came down on the other side at the last passenger car, climbed inside, and breathlessly stomped their feet to warm them without anyone seeing them.

Relieved and shaken, Mercy escaped her companion and holed up in the washroom, since there were almost no passengers left and no one would be waiting for her to finish. She spent ten minutes unfastening her hair and shaking it, trying to air it enough so that when the locks brushed up against her face she didn’t smell the miasma of the rearmost car. Then she washed her hands, face, and neck.

By the time she’d dragged herself back to her seat, the crews were wrapping up the last of their work and the train was being reboarded by the soldiers, porters, and engineers who would carry them the rest of the way west. Outside her window Mercy saw Horatio Korman talking with the captain, their faces leaning together conspiratorially. She also saw two of the captain’s underlings shaking their heads as if they couldn’t believe that the two men weren’t fighting to the death on the spot.

When Mercy saw that the ranger was about to board, she hurried over to the front door, hoping for a chance to ask him what he’d learned at the stop. But when she got there, she found the two Mexican inspectors, who had also been watching the captain and the Texian with a mixture of nervousness and uncertainty.

Inspector Galeano stopped her and asked, “Do you think they’ll make us leave the train? We’re so close. We only need to make it to the next stop,” he said.

She said, “No, nobody’s going to make you leave the train. They’re just talking out there, and believe me, they ain’t friends. I’m going to try and have a word with the Texian myself in a minute, if you’ll excuse me.” Then the car door opened and the man in question stepped in.

Ranger Korman paused to see Mercy speaking with the Mexicans. He tipped his hat and said, “Mrs. Lynch,” then, to the other men, “Fellas. How about the four of us sit down here for a spell?”

Mercy was so surprised, you could’ve knocked her over with a feather. The car was otherwise unoccupied, so it took no great feat to seat everyone in one of the sleeper compartments for the illusion of privacy. Mercy sat beside the ranger, and they both faced the inspectors.

She asked him, “Did you get your telegrams? Did you really share them with the captain?”

“I got them, yes. And I shared most of them, just like I promised.”

Inspector Portilla said, “I don’t understand.”

The ranger waved his hand. “We might be on the verge of finding your missing people.”

“That is what we hope!” Portilla replied.

Galeano asked, “Was that your mission, too, upon this train? We could’ve spoken sooner.”

Korman said flatly, “No, we couldn’t have, but, yes, it pretty much is my job to find out what’s been happening. Now, you and me,” he indicated the pair of them and himself, leaving Mercy out of the equation for the moment, “we’re all men working for our governments. My government didn’t have anything to do with what happened to your men, and your government didn’t have anything to do with it. So we’ve got a problem on our hands: the kind that can blow up into open war, because everybody’s pointing fingers. And if there’s one thing Texas don’t need right now, it’s another front to keep track of, do you hear me?”

The inspectors exchanged a glance and nodded. “Your support of the southern cause—”

“Is irrelevant to this conversation,” he interjected. “Except for how those stubborn jackasses are still bound and determined to take this train. You and me, we don’t want them to take this train. We want them to leave this train alone, so that we can all find our ways to our destinations. Can we agree on that much?”

Everyone nodded, and Inspector Galeano asked, “Why are they so determined to stop this train? I know that the engine is a war device, but we are nowhere near any of the war fronts.”

“Gold,” said the ranger. “Tons of it. She’s seen it,” he said, cocking a thumb at Mercy.