In fact, I’m starting to sweat. The tunnel walls are heating up my air. It’s uncomfortable, but not too bad. I can open the Hail Mary’s inner airlock door if I want my climate control to take over. Then our life-support systems can fight it out. They’ll keep the hot side hot and I’ll keep the cold side cold.

Even with the sweat forming on my brow and the strong ammonia odor making my eyes water, I press on. I’m just too curious not to. Could anyone blame me?

There are at least twenty little hexagons on this wall. They’re all different colors and textures and I think a couple of them might be translucent. I should catalog each one and figure out if I can identify what they’re made of. Looking closer, I see there’s a definite seam running along the edges of the hexes.

That’s when I hear a sound come from the other side:

Knock, knock, knock.

Chapter 10

They knocked, so it’s only polite for me to knock back. I know that wall is going to be hot, so I rap my knuckles on it as fast as I can.

I knock three times, just like they did.

There’s no immediate response. I take a good long look at the hex wall. There are forty hexes, I’d say, and each one seems to be unique. Different materials, maybe? I feel like I’m supposed to do something here, but what?

Are they watching me? I don’t see anything that looks like a camera.

I hold up my finger and point back to my airlock. I don’t know if they can see me or if they have any idea what that hand gesture means. I kick off the hex wall and back to the airlock, and then I open the inner door. Why not? The pressure is the same on both sides. It’s okay to leave the airlock open. If there’s a pressure loss in that tunnel, the air leaving the ship will slam the inner airlock door shut and I’ll get to stay alive.

I go to the lab and pack a bag with a few choice items, then return to the tunnel.

First I tape LED lamps to various spots along the tunnel and aim them at the hex wall. Now I can see what I’m doing, at least. I pull out my trusty handheld x-ray spectrometer and scan one of the hexes. It’s xenonite. Almost the same composition as the cylinders they sent me earlier.

Almost.

There are a few differences in the trace elements. Interesting. Maybe xenonite is like steel—lots of different recipes? I check the next hex over. Another slightly unique combination.