This scene comes about midway through the book, as our teenage sleuths, Paul and Jael Wardhey, are tracking down the mysterious Cynthia, who seems to have a knack for disappearing in plain sight.

Jael’s muscles were burning with a dull ache by the time she finally got to the base of the gently-sloping ridge. As she had suspected, the tracks went beyond it and then turned behind it. Snapping her crutches back behind her, Jael knelt and began crawling up the shallow hill.

“Did you see something?” Paul asked sharply in her earphones. Jael nearly cried out in surprise. She had forgotten her brother was watching.

“No!” she growled. “Just using some of that caution you’re always urging on me.”

“Hmm, she can be taught,” her twin mused mockingly.

“Teach this,” she said, making a rude gesture at the helmet’s pickup. She resumed her crawl.

It seemed to take forever, but at last she poked her clear helmet over the crest of the ridge.

If she had been expecting a Lair Of Villainous Moon Nazis, she would have been sadly disappointed. Actually, she was still disappointed, even though she hadn’t really been expecting Moon Nazis. “Aaaand it’s an ordinary minestead,” she said. “Nothing sinister or mysterious about it at all. The 3-D printed dome looked just like any hundred other single-family minesteads that dotted the lunar landscape around Thunderhead like freckles around a – giant, sprawling tumor, she supposed, and discarded that image as unnecessarily bleak.

“Except why is the President of Yuland-Weytani visiting an ordinary minestead?” asked Paul. “Or alternatively, why does he own an ordinary minestead? Because those are pretty much the options, you know?”

“Maybe it’s his private getaway?” said Jael.

“Sure,” said Paul. “And he didn’t spend the extra money on making it look more impressive than any other minestead because he’s saving his billions this month? And even if that were the case, we don’t know what any of this has to do with Cynthia.”

Jael gave a decisive nod, one that Paul would be sure to see by the way the camera bobbed. “Right,” she said. “You’re right. I’m going down there.”

“What? Wait!” said Paul, thinking better of his analysis.

“You’re right, Paul. None of this has solved our mystery. So I’m going down there and checking it out. There aren’t any rovers on the surface, and this place isn’t big enough for a pressurized garage to store one in. I can stay away from the windows. I’m in a blind spot right now. I’m going.”

She could hear Paul’s breathing. “All right,” he finally said.

Jael allowed herself to drift down the side of the ridge, walking on her crutches alone, feet tucked under her. There seemed to be no lights streaming from the few ports in the dome. She knew that the minestead would have been built with at least as much volume below the lunar surface as above it, though, so the lack of light didn’t mean no one was home. It just meant no one was likely to be looking out the windows right now.

There was no place to hide on the flat, lunar plain, so Jael made for the only cover available as quickly as she could: the curving minestead wall. Which she needed to reach anyway. As soon as she reached it, she flattened herself against it and pulled from a beltpouch a device that looked like an array of suction cups. She hooked it into her HUD and flipped the sonic sensors on, passive only.

She listened for quite some time, but her ears heard no sounds being made inside the lifeless-looking minestead, nor did the lines indicating noise flicker, nor any image form on her helmet.

Carefully, she pushed herself out of contact with the dome. “Go active?” she murmured.

“That’s risky,” said Paul.

“That place is quiet as a tomb,” Jael snorted. “There’s no one home.”

“That why you made sure you weren’t touching the wall before you called in?” asked Paul. Sound couldn’t travel in vacuum. But sound could very definitely travel through the surface of the Moon, and through outsuits or walls, or any other solid object on its surface. What Jael had done was only good sense. She started to reply when Paul said. “What if they’ve set an alarm that can detect your detector?”

Jael forced herself to think rather than reply angrily. Finally she said, “Maybe, but everyone knows Rescue uses sonic probes. We have to. Spies should have something more sophisticated.”

She knew Paul was right. Using active sonics – which, like ancient submarine sonar, would send a pulse of sonic energy through the minestead, revealing its spaces and objects – was far easier to detect than the passive sonics which she had been using up to now. Detecting passive sonics was like trying to listen for someone listening at your door: almost impossible. Detecting active sonics was more like listening for someone knocking on your door. If anyone was in there, they might be able to hear her even if they weren’t paying attention.

“Then what are you going to do if someone is there and they do hear you?” Paul asked.

Jael fumed. Sometimes she thought of her brother as a very annoying external conscience that wouldn’t go away and wouldn’t shut up. If it had been just her, she thought, she’d have much preferred to ignore that question and simply trust that she could handle it in the unlikely event it came up.

Which, she reflected, was – much as she hated admitting it – why it probably was a good thing that he was there. She forced herself to think through the problem. “If that happens,” she finally said, “I’ll just tell them that I’m from Emergency Rescue, and we got a call that we traced to this location, so sorry Sir or Madam that I troubled you, please excuse me because Emergency Rescue is expecting a status update and we really need to make sure this glitch is fixed and doesn’t happen again.”

After a few seconds, Paul said, “Okay, yeah. It tells them you’re in contact with people and it sounds plausible. They won’t feel threatened if they’re up to something, and even if they do, they know that disappearing you will only attract more attention that they don’t want. Go for it.”

With permission from Brother Conscience, Jael powered up her sonic probes and send sound waves pulsing through the minestead structure. An interior map blossomed into view on her HUD map. “Are you seeing this?” she asked Paul.

“Yeah,” he answered. “Doesn’t look like there’s much to see, though. Looks pretty typical.”

“So the mystery remains a mystery,” Jael said. “Well, onward, then.”

“What do you mean, ‘onward?'” asked Paul.

Jael didn’t bother answering this one, since she had long ago decided what she was going to do. How long would it take Paul to figure it out? She pushed herself upright and began crutching toward the minestead airlock.

“Jael, what are you doing? Jael, can you hear me?”

“Yes, and you’re being awfully loud,” she said.

“Then answer me what you’re doing, dammit!”

“Language, little brother. And your voice is very high-pitched, too. You’ve definitely finished puberty, right?”

“Jael, you cannot just break into these people’s house.”

“Um, yes I can. We established that. I showed you my access card, didn’t I?”

“It’s not legal for you to break into these people’s house!”

“Oh, it’s not legal,” said Jael. She flourished the universal access card. “Why didn’t you say that in the first place? Hey, maybe you’d better call the police.”

“I am the police!” shouted Paul.

“Wow, that was fast work.”

Her brother sputtered and audibly brought himself back under control. “Jael Wardhey,” he said icily. “I am informing you as a deputy of Thunderhead colony that you are committing felony trespass.”

“Go breathe vacuum,” Jael said easily, and inserted her card. “If nothing’s wrong in here, then nothing’s wrong. If something’s wrong in here…”

“Then we won’t be able to use anything you find as evidence!” said Paul. “The United States Bill Of Rights still applies up here, you know. It’s in the colony charter!”

The airlock’s outer door opened silently, revealing the standard, dimly-lit chamber.

“If something is as wrong in here as we’re afraid it is, then we’ll be able to get Cynthia to tell us and come back with a warrant. But if you’re really determined to press this, call Mom and have me arrested. Because you haven’t been part of or encouraged this in any way.” She paused. “Oh, wait: that’s wrong, you’re in it up to your neck.”

“The people who live here are going to see you’ve been here.”

“Well, not unless I’m an idiot. Or their airlock is malfunctioning pretty badly.” The outer door closed, and she sensed the electromagnetic pulse that static-charged the moon dust she had tracked in. It leapt to the filters lining the walls and was gone without a trace.

“You’ve left tracks outside,” her brother growled. “And your tracks are pretty distinctive.”

“Sure are,” said Jael. “I can just imagine someone trying to figure them out. I wonder how long it will take them to come up with ‘crippled girl on crutches?’ How many advanced tripod-propelled drones will they imagine before getting to that one?”

The airlock had pressurized. Carefully, she removed her helmet from its locking collar. Leaving it connected to her sonic sensors, she placed their pads in contact with the floor and turned the sensitivity to maximum gain. She explained this to Paul, and commanded it to relay its information through their link. “You’ll have to filter out my footsteps,” she said. “But hopefully, we’ll get a warning if they come back.” She hit the panel for the inner door. No need for two locks on a minestead, after all. It hissed open. Jael stepped inside. The lights came on in response to a human presence.

“Douse those!” whispered Paul.

“Why?” asked Jael. “How will I see?”

“You figured these people weren’t home because no lights were showing,” Paul said, speaking quickly. “What will they think if they come home and see the lights are on? Now use your convirscer’s lowlights!”

Jael swallowed, understanding immediately. “Lights out,” she said. Immediately, it went dark. Jael put her convirscer to her face and felt the earphones and blinders extend. The lowlight function projected her surroundings in VR, in slightly faded color. Although she would already be in a lot of trouble if anyone came home while she was in the minestead, there was no point in tipping off its owners that they had an intruder and yielding even the dubious value of the element of surprise.

“What do you see?” hissed Paul.

“Do you think the whispering makes it less likely that the people who aren’t here will hear you through several kilometers of vacuum?” asked Jael acidly, fighting the urge to whisper herself. It seemed wrong to talk in a normal voice while trespassing.

“I think hurrying the hell up makes it less likely you’ll be found,” Paul returned, now in a normal voice. “So look around and get out of there.”