Astrophage can, apparently, do this in either direction. It takes heat energy and somehow turns it into mass. Then when it wants the energy back, it turns that mass back into energy—in the form of Petrova-frequency light. And it uses that to propel itself along in space. So not only is it a perfect energy-storage medium, it’s a perfect spaceship engine.

Evolution can be insanely effective when you leave it alone for a few billion years.

I rub my head. “This is just crazy. In a good way, though. Is it internally producing antimatter, you think? Something like that?”

“We do not know. But it definitely increases in mass. And then, after using light as thrust, it loses mass appropriate to energy released.”

“That’s…! Dimitri, I want to hang out with you. Like—can we hang out? I’ll buy you a beer. Or vodka. Or anything. I bet there’s an officers’ club on this boat, right?”

“It would be my pleasure.”

“Glad you’re making friends,” said Stratt. “But you’ve got a lot of work to do before you start hitting the bars.”

“Me? What do I have to do?”

“You need to design and create an Astrophage-breeding facility.”

I blinked. Then I shot to my feet. “You’re going to make an Astrophage-powered ship!”

They all nodded.

“Holy cow! It’s the most efficient rocket fuel ever! How much would we need to—oh. Two million kilograms, right? That’s why you wanted to know how long it would take to make that much?”

“Yes,” said Xi. “For a one hundred thousand kilogram ship, we would need two million kilograms of Astrophage to get it to Tau Ceti. And, thanks to you, we now know how to activate the Astrophage and make it generate thrust at will.”

I sat back down, pulled out my phone, and launched the calculator app. “This would take, like… a lot of energy. Like, more energy than the world has. It would be around ten to the twenty-third Joules. The largest nuclear reactor on Earth makes about eight gigawatts. It would take that reactor two million years to create that much energy.”

“We have ideas for finding the energy,” said Stratt. “Your job is to make the breeder. Start small and get a prototype going.”

“Okay, sure,” I said. “But I didn’t exactly love the ‘militaries of the world’ grand tour on the way here. Can I take a passenger jet home? Coach is fine.”

“You are home,” said Stratt. “The flight hangar is empty. Just tell me what you need—including staff—and I’ll make it happen.”

I looked at the others in the conference room. Xi, Voigt, and Dimitri all nodded. Yes, this was real. No, Stratt wasn’t kidding.

“Why?!” I demanded. “Why the heck can’t you just be normal, Stratt?! If you want fast military transport, well, okay, but why not just work at an air base or something sane people would do?!”

“Because we’ll be experimenting with a bunch of Astrophage once we breed it up. And if we accidentally activate even a couple of kilograms of that stuff, the resulting explosion will be bigger than the largest nuclear bomb ever made.”