There was something different about the ground outside the crack. No grass grew there, and the ground was not the black soil of this alien region. Rather, it seemed to be coated in a fine, yellow powder.

“Codex,” Cade coughed. “What is this place?”

The drone flashed blue light and spoke.

“Remnant is the SS Marine Sulphur Queen, which disappeared when traveling through the Bermuda Triangle in 1963. It had a crew of thirty-nine and carried a tank of 15,260 tons of molten sulfur in its hold.”

Cade staggered away, giving himself a break from the smell. He allowed himself to collapse on the ground, and the others followed. Here, the stench was just about bearable.

“The … Sulphur Queen?” Scott said first. “What kind of name is that? Sounds like Grace after a bean stew, if you know what I mean.”

He winked, only to wheeze a moment later as Grace’s elbow found his belly.

“Not funny, Scott.”

Cade wondered how thoroughly the Romans had investigated the ship. It didn’t look like there was anything of use left there. Scrap metal perhaps. But whatever was inside had likely rusted away already.

Nor was the ship a wartime vessel. There would be no rocket launcher here. No guns, nor any other weapons. He would explore the ship, but he had little hope of finding anything that would solve their siege weapon problem.

“So, sulfur,” Amber said matter-of-factly.

Cade rubbed his eyes and forced a smile. “Yeah?”

“Well … that’s it, isn’t it? That’s what Abaddon gave to the Romans. And I guess, that’s what he gave us.”

He rubbed his eyes some more. This was going to be more complicated than he had thought. “I mean, I don’t—”

“Acid!” Yoshi announced triumphantly.

Cade stared at him.

“We make sulfuric acid,” he explained. “I remember it from chemistry class. Remember, Bunsen burners and all that?”

Cade rubbed his chin. It was not a bad guess. Though he doubted they would ever be able to make anything potent enough to eat through a door of what he imagined was solid metal or stone.

“Codex, what is the simplest way to make sulfuric acid from raw sulfur?” Cade asked.

“Burn sulfur to create a gas, and direct the gas into a reactor bed with vanadium pentoxide catalyst and oxygen gas to make sulfur trioxide—”

Cade held up his hand.

“That’s enough, thank you, Codex.”

Yoshi sighed under his breath before collapsing back and closing his eyes. “Well, that’s all I’ve got. Anyone else?”

“Unless we can build a reactor and find some vanadium whatever, I don’t think we can make acid,” Amber said. “Let alone something powerful enough to be of any use.”

“All right, all right,” Yoshi groaned. “I get it, bad idea.”

“Yoshi is right, sort of,” Cade said, trying to settle the tension that had crept in. “It’s chemistry, right? Sulphur doesn’t do anything but smell on its own. I think if you burn it, the gas is quite toxic, but I don’t think we can smoke the Grays out—normal smoke would work just as well.”