“Come on,” he said. I followed him through the back door into the residence. The tiny living room was palatial compared to my humble shithole.

Dad’s place had two coffin bunks along one wall. Very common among lower-class Artemisians. Not as nice as bedrooms, but they allowed privacy, which was good. I grew up in that house. I did…stuff in that bunk.

He had a cook nook with an actual flame-based stove. One of the few advantages to living in a fireproofed room. Way better than a microwave. You might think a real stove meant tasty meals, but you’d be wrong. Dad did his best, but Gunk is Gunk. There’s only so much you can do with algae.

There was one big change, though. Along the back wall a meter-wide sheet of metal ran from the floor to the ceiling—it wasn’t even close to vertical. I’d estimate 20 to 30 degrees off true.

I pointed to the new feature. “What the hell is that?”

Dad looked over to it. “It’s an idea I came up with a while ago.”

“What’s it for?”

“Work it out.”

Ugh! If I had a slug for every time he’d said that in my life…Never a straight answer—everything had to be a goddamn learning experience.

He crossed his arms and watched me like he always did during these little quizzes.

I walked over and touched the sheet. Very sturdy, of course. He never did anything half-assed. “Two-millimeter sheet aluminum?”

“Correct.”

“So it doesn’t need to handle lateral force…” I ran my finger along the intersection of the sheet and the wall. I felt small bumps every twenty centimeters. “Spot welds? That’s not like you.”

He shrugged. “It might be a stupid idea. I’m not ready to commit.”

Two hooks jutted out from the top of the sheet, just centimeters from the ceiling. “You’re going to hang something on it.”

“Correct. But what?”

I looked it up and down. “This weird angle is the key…got a protractor I could borrow?”

“I’ll save you the trouble,” he said. “It’s twenty-two point nine degrees from vertical.”

“Huh…” I said. “Artemis’s longitude is twenty-two point nine…ah. Okay, I got it.” I turned to face him. “It’s for prayers.”

“Correct,” he said. “I call it a prayer wall.”

The moon always points the same face toward Earth. So, even though we’re in orbit, from our point of view, Earth doesn’t move. Well, technically, it wobbles a bit because of lunar libration, but don’t worry your pretty little head about that. Point is: Earth is fixed in the sky. It rotates in place and goes through phases, but it doesn’t move.

The ramp pointed at Earth so Dad could face Mecca while praying. Most Muslims here just faced west—that’s what Dad had done all my life.

“How will you use it?” I asked. “Special straps or something? I mean—it’s almost vertical.”

“Don’t be ridiculous.” He put both hands on the prayer wall and leaned forward onto it. “Like this. Simple and easy. And it’s more in keeping with Qiblah than facing west on the moon.”

“Seems silly, Dad. It’s not like Muslims in Australia dig a hole and face down. You think Muhammad’s going to be impressed?”

“Hey,” he said sharply, “if you’re not going to practice Islam, you don’t get to talk about the Prophet.”

“All right, all right,” I said. I pointed to the hooks. “What are those for?”

“Work it out.”

“Ugh!” I said. Then I grudgingly added, “For attaching a prayer rug?”

“Correct.” He walked to a table near the cook nook and sat in one of the chairs. “I don’t want to poke holes in my usual prayer rug, so I ordered another one from Earth. It’ll be here in a few weeks.”

I sat in the other chair, where I’d had countless meals throughout my life. “Do you have a shipping manifest number? I can arrange to get it here faster—”

“No, thanks.”

“Dad, there’s nothing illegal about pulling strings to—”

“No, thanks,” he said, a little louder this time. “Let’s not argue about it.”

I gritted my teeth but kept quiet. Time for a change of subject. “Weird question: Have you ever heard of something called ‘ZAFO’?”

He raised an eyebrow. “Isn’t that an ancient Greek lesbian?”

“No, that’s Sappho.”

“Oh. Then no. What is it?”

“No idea,” I said. “Just something I saw in passing and wondered about.”

“You’ve always been curious. You’re great at finding answers too. Maybe you should put your genius to work on something useful for a change.”

“Dad,” I said with a hint of warning in my voice.

“Fine.” He folded his arms. “So you need welding equipment?”

“Yeah.”

“Last time you had access to my equipment it didn’t go well.”

I stiffened. I tried not to break eye contact, but I couldn’t help myself. I looked at the floor.

He took a softer tone. “I’m sorry. That was uncalled-for.”