Hammering in a piton wasn’t simple in zero gee. There was nothing to hold him to the “ground,” so after each swing, he would rotate away from the spike. He’d foreseen this, of course, and brought along a hand drill to make a preliminary hole.

I held a light for him but looked away from it to preserve my night vision. The sky was beautiful, the stars brighter than on Earth, the Milky Way a glowing billow across the darkness. I wished I knew the constellations well enough to tell whether they were different. Orion looked about the same. Paul pointed out where our Sun was. A bright yellow star, but there were brighter ones.

We had safety tethers attached to the air lock. After the piton was secured, Paul jetted across first, unreeling the guideline behind him. I followed him hand over hand, trying not to tangle the three lines.

The air lock on the starfish-shaped craft was a barely visible lip. Paul drilled and hammered a piton right in front of it. He secured the guideline to give it about three or four feet of slack; if you held on to it, you could walk, after a fashion, from one air lock to the other.

We returned to our own ship to relax for a few minutes and ensure we’d be going over with full air tanks and empty bladders. There was no strategy to discuss; we’d just keep our eyes and minds open.

Fly-in-Amber went over between us, moving with characteristic caution. I didn’t mind going slowly. It was a long way down.

When we got to the air-lock lip, Paul opened the radio circuit—I heard a slight click—but before he could say anything, Spy’s voice said, “Come in,” too loud and too clear. The lips parted to reveal a red glow.

“Returning to the womb,” I said. We went in, and the lips closed behind us. The small red light inside my helmet, an air warning, glowed green.

“Is this safe to breathe?” Paul asked on the radio.

“If I wanted to kill you,” Spy said, “I wouldn’t have to go to this much trouble. This is exactly the same pressure and composition as you breathe over there.” He stepped in out of the gloom and made a circle with one hand. “Paul, get your feet under you. I’m going to turn on some gravity.” As the light increased, so did the feeling of weight. It was very feeble, though; much less than Mars.

“What kind of gravity?” Paul asked.

“Triton. About one-twelfth Earth’s gravity; less than a third that of Mars.”