I pull the workpiece out, dust off the aluminum shavings, and hold it up to the tunnel. “How’s this?”

“Very good!” Rocky says. “We will need many many many chain links. More molds means I can make more at one time. You can make many molds, question?”

“Well.” I look in the supply cabinet. “I have limited amounts of aluminum.”

“You have many items in ship you no use. Two beds in dormitory, for instance. Melt them, make blocks, make more molds.”

“Wow. You don’t do anything by half-measure, do you?”

“No understand.”

“I’m not going to melt a bunch of stuff. How would I even do that?”

“Astrophage. Melt anything.”

“You got me there,” I say. “But no. The heat would be too much for my life-support system to handle. That reminds me. Why do you have so much extra Astrophage?”

He pauses. “Strange story.”

I perk up. Always up for a strange story. He clicks along his tunnel and sits in a slightly wider section. “Science Eridians do much math. Calculate trip. More fuel mean faster trip. So we make much much much Astrophage.”

“How’d you make so much? Earth had a very difficult time makingit.”

“Was easy. Put in metal balls with carbon dioxide. Put in ocean. Wait. Astrophage double, double, double. Much Astrophage.”

“Riiight. Because your oceans are hotter than Astrophage.”

“Yes. Earth oceans are not. Sad.”

When it comes to Astrophage manufacturing, Erid was born on third base. The whole planet is a pressure cooker. Twenty-nine atmospheres at 210 degrees Celsius means water is liquid on the surface. And their oceans are far, far hotter than the Astrophage critical temperature. They just put Astrophage in the water, let it absorb heat, and breed.

I’m jealous. We had to pave the Sahara Desert to breed up our Astrophage. All they had to do was throw it in the water. The stored heat energy of Erid’s oceans is ridiculous. A whole bunch of water—multiples of Earth’s total oceans—holding a temperature around 200 degrees Celsius or more. That’s a lot of energy.

And that’s why they can take a century or so to solve the problem while Earth is going to freeze in a few decades. It’s not just their air storing heat. Their oceans store even more. Born on third base. Again.

“Science Eridians design ship and fuel requirements. Journey to take 6.64 years.”

That trips me up for a moment. 40 Eridani is ten light-years away from Tau Ceti, so you can’t get from one to the other in less than ten years from Erid’s point of view. He must mean 6.64 years of time experienced by his ship thanks to time dilation.

“Strange things happen on trip. Crew sick. Die.” His voice lowers. “Now I know was radiation.”

I look down and give him a moment.