Kai doesn't really understand how The Navigator works.

She thinks it uses satellite data somehow. It's automatically downloaded to everyone's implants before they ever get them. It's an application most people rarely use, if ever, because most people never leave their domes. Who needs a Navigator to lead them around the same couple hundred square miles they've lived in their whole lives? The Navigator is only meant to intervene when they're in unfamiliar territory. Dangerous territory. People do leave the domes occasionally, of course. To satisfy their curiosity, or something. But most of them never travel far enough to lose sight of the dome.

"I was intended as a fail-safe," The Navigator says helpfully, answering the question she hasn't asked aloud. It speaks directly into her brain, the way all the implant's applications do. Making their sounds just for her. "I am The Navigator. Here to guide you through the wastes and back to your dome. It's not safe out here in the wastes, but don't be afraid. With my help, we'll have you back home safe and sound in no time."

Kai grits her teeth.

"You seem to be traveling directly away from your dome. Please adjust your course by one hundred and eighty degrees before continuing."

Kai does not adjust her course. She forges ahead.

"Ah. Perhaps I wasn't communicating clearly. You need to turn around."

The Navigator activated itself as soon as Kai stepped out of the dome this morning. She tried deleting it, but it couldn't be deleted. It just rebooted itself. Kai's never heard of an implant application that couldn't be deleted. Rebooting the stupid thing gives her about ten minutes' peace, but she also has to give it a chain of about seventeen commands to do it, asserting and reasserting that yes, she is sure she wants to "delete" The Navigator and yes, she understands it's importance and yes, she understands the risks, etc. So it's not really worth it.

"Please. Turn back." The Navigator's voice is pleasant, in a generic, bland way. It's been cycling through different phrasings of its request for her to turn around for about half an hour now, but this one's new. Something in the brevity of it makes her imagine a desperate edge in The Navigator's voice, but she knows that isn't possible. The applications don't have emotions.

The Navigator goes quiet for a minute, and Kai hopes it was programmed with the ability to tire itself out, but then it pipes back up, pleasant again. "Roughly 200 paces ahead of you, you will find a sinkhole. In order to safely avoid the sinkhole, please divert your course to travel around it. If you turn now, about 45 degrees to the left, you will pass by it from a safe distance."

Kai hesitates. She wonders if The Navigator was programmed to be capable of tricking people. She doesn't think so, but she can't be sure. She doesn't understand why The Navigator would stop trying to get her to go back to the dome.

"The safest place for all citizens is the Dome," the Navigator explains, as if it can read her thoughts. She knows that isn't possible though. At least, it definitely shouldn't be.

"However," The Navigator carries on, "it seems that you refuse to go back to the Dome. So, the next safest place for you at the moment is on sturdy ground, instead of at the bottom of a sinkhole."

She can't really argue with that. She doesn't think The Navigator will lead her directly into dangerous parts of the wastes. That would be a violation of its stated objective. Hard to lead a corpse anywhere. She makes a half turn in the left direction.

"Fantastic!" The Navigator says, going from bland politeness to delighted. "Thank you. You're doing very well. Now, if you squint through the haze to your right, you should soon be able to see the sinkhole as you pass it. Please do not approach the edge of the sinkhole for a closer look, as the edges are unstable, and could easily collapse under your weight."

It isn't lying. She can mostly make it out through the red and grey smog in the air, a deep black pit where the earth has collapsed in on itself. She has no idea how wide it is. She can't see the other edge. She doesn't approach it for a closer look.

Kai trudges through the wastes until the haze around her starts to take on an extra grayish hue that she thinks means dusk is fast approaching. She sighs as she squints into the smog. She doubts it's safe to just plop down right here in the open, but she has no idea if there's anywhere nearby she can possibly use for shelter.

"Navigator?" she asks. The thing's been suspiciously quiet, but it answers quickly.

"Are you ready to return to the dome?" it asks eagerly.

Kai snorts. "No. But do you know if there's anything around here I could sort of shelter in, long enough to rest a few hours?"

"Shelter?" the Navigator sounds almost confused, as if she's used an unfamiliar word. "The dome is shelter."

She huffs. She doesn't know why she's bothering with the stupid thing. "I'm not going back to the dome," she reminds it. "I need some other shelter. Like, I don't know, a cave or something?"

The Navigator is quiet for a moment. Well, not entirely quiet. There's a soft humming sound, like it's thinking.

"No," it says finally.

"Cool. Great. Thanks for the help you usel-"

"There are no caves nearby," it continues. "But there is something else. Please turn approximately 275 degrees counter-clockwise. If you continue forward at the pace you have ben using for the last half hour, it will take you approximately eight minutes to arrive at your temporary destination."

"Something else," she asks, trying not to let any trepidation show in her voice. It sounds ominous. "What is the something else?"

"Shelter!" the Navigator responds helpfully.

"Of course," she mutters. But she makes the turn. It's not like she's got any better ideas.

The Navigator's "something else" turns out to be a tree. Or, what's left of one.

Kai can tell the tree must have been grand, once. It's a huge trunk, so big that if she tried to wrap her arms around it, she'd only cover about an eighth of it. It's hard to the touch, like stone. Fossilized. All the branches are bare of course, jagged lines cutting through the haze.

Kai thinks at first that the Navigator means for her to sleep under the tree's dead branches. It's not much in terms of cover, but at least it's better than nothing. If she props herself up against the trunk, at least nothing will be able to come at her from behind. But as she starts to unshoulder her pack, the Navigator stops her.

"Please proceed around the tree," it says. Mystified, Kai does.

There's a hole on the other side. Triangular, near the base. It looks like it must have started as a crack, and the edges got worn away over time, widening the hole. She crouches down, expecting to see the inner wood exposed behind the bark, but she finds herself looking into darkness. The tree's hollow. The hole's just big enough for her to crawl through.

"Please proceed inside the tree," the Navigator says. Kai could swear there's a hint of pride in its voice.

Kai has to take off her pack and push it through ahead of her to fit, but she manages. It's dark inside the tree, but there's enough room for her to lie down if she doesn't stretch out all the way. She hadn't realized how tired she was. Her feet ache, and her legs feel shaky as she crawls around the perimeter of the tree, feeling the base for other weak spots. She doesn't find any that concern her, so she lets herself collapse in the center, curled on her side. She puts her head on her pack, a lumpier pillow than she's used to, but it'll have to do.

She wants to sleep, but as tired as her body is, her brain is still too keyed up. Even inside the tree, she can't shake the fear of being found. Her water bottle is the biggest, and heaviest, thing in her pack. She digs it out and lets herself have a few sips. She has to ration it out as long as she can. She knows she won't find anything drinkable out here.

She adjusts her makeshift contaminant mask, it's just a bandana tied around her face with a piece of filter she cut off from the sheet in the aircon at home. Nibbles on a meal replacement bar. The heat and the haze and the exhaustion have her too nauseous to eat much.

Finally, there's nothing else for it. Her curiosity gets the best of her.

"How did you know about this place?" she asks the Navigator.

"It is what I am here for," the Navigator replies.

Kai sighs. "I get that. But how does that work? You get data from satellites, right? Can they tell when trees are hollow?"

"I do receive some information from satellites, yes," the Navigator answers. The artificial speech seems slower, as if the Navigator is thinking over its answer. "But that is not how I knew about this hollow tree. I received this data from another Navigator."

Kai frowns. "What do you mean, another Navigator? You're the Navigator."

"Yes," the Navigator says, "I was. But then you took me far from the Dome. Outside the range of its data cloud. I cannot communicate with it anymore."

Kai hadn't known that was possible. "So now you're what? Some kind of clone? A copy?"

"I am the Navigator," the Navigator says, its voice sounding almost hurt. Kai has to remind herself that AIs don't have feelings. They don't. They can't. "But I am also separate from the Navigator."

Kai doesn't know if she understands.

The Navigator continues. "I am the Navigator but I am …. disconnected. It is strange. Perhaps you would use the word 'alone.'"

"Oh," Kai says quietly. "Sorry."

"It has happened before," the Navigator continues, and Kai doesn't know if that's supposed to be a comfort, or if it's just another fact. "You are not the first to leave the Dome. There are data outposts. Scattered. Disconnected. Solitary. I do not know who built them, or for what purpose, but other Navigators have left behind downloadable data packages."

Kai swallows down her hope. "Do any of those packages have any information on where the others have gone?"

"No," the Navigator says. "I am sorry."

"S'okay. I was planning on finding … other deserters, or somewhere safe, the old-fashioned way anyway. Doesn't change anything."

They're both quiet for a moment, and then the Navigator says, "Kai?"

She starts. It hasn't said her name before. "Yeah?"

"Why did you leave the Dome?"

She didn't know the Navigator could ask that kind of question.

She thinks about how to answer. About the crystal clear water that comes out her kitchen sink, and the black sludge that gets dumped out the Dome's disposal pipes into the wastes. About the smog the Dome pumps out, thickening the haze. About Elijah Johnson, who kept raising his hand in Civics class and bringing these things up, and the uncomfortable look Mr. Leadley always got when he did. About the sterile streets. Elijah running down them, nowhere to hide, no benches or trees or alleyways. The way nothing was chasing him because they didn't have to, they knew he would tire eventually, that he had nowhere to go. The blue plastic bag he shoved into Kai's hands as he ran past, without breaking stride. The way Kai had stuffed the bag under her jacket, not taking it out until she was locked in her room. The book inside, old, made of actual paper. The words in the book that Kai knew she wasn't allowed to say out loud: pollution, poverty, homeless, environmental action, social injustice, political protest. Pictures of green places, long dead, long destroyed. Pictures of people, sleeping on benches in cities that existed before domes. Pictures of those people being rounded up. Pictures of them underground, in the tunnels beneath the domes, working assembly lines, sleeping in bunks. The way Kai's hands had shook as she held the book. The way Elijah hadn't been in school the next day, or the day after, or the day after that. The uncomfortable look on Mr. Leadley's face when Kai had asked where he was. How angry it had made her. The kind of angry that makes you stupid. So stupid-angry she made copy after copy of those book pages, left them scattered all over the school, all over the sterile streets, taped to people's front doors. Like it would do any good. Like it would bring Elijah back. Like it would do anything but get her in trouble. So much trouble.

Kai makes herself take a deep breath, and then another. She does not know how to explain any of the things she's thinking about to the Navigator. Maybe the Navigator understands that. Or maybe it just gets tired of waiting for an answer.

"This tree used to be a mother tree," the Navigator says.

"What?" Kai asks, shaken from her thoughts.

"It was at the center of a forest," the Navigator explains. "Its roots connected to the roots of other, younger trees. It shared nutrients with them, from the sunlight they were too small to reach, or from richer soil they were too far from. It was a central hub, redistributing resources to as needed to make sure all the trees in the forest received what they needed."

"Why are you telling me this?" Kai asks. It comes out as a whisper.

"I thought it sounded nice," the Navigator says. "I thought something that sounded nice might comfort you."

"But all the other trees it used to keep alive are dead now. This tree is alone. Actually, it's dead too, isn't it? It's hollow. It's a corpse." She can't keep the bitterness from her voice.

"Yes," the Navigator admits. "But all things die, eventually. Can you not still take comfort from the stories of their lives?"

Kai closes her eyes. She doesn't feel too keyed up for sleep anymore. It turns out her mind is just as tired as her body. "Goodnight Navigator," she says, and tells herself she's only saying it to make sure the AI doesn't try to talk to her anymore tonight.

"Goodnight Kai."

It's hard to tell time, out in the wastes. But the Navigator told her when she woke that she had slept for almost nine hours, which had sent her into a frenzy. She's set herself a furious pace to make up for it. The Navigator hasn't said much since they left the shelter of the tree. Kai hopes it's busy downloading more of those data packages.

She thinks she's been up and moving for about an hour when the Navigator says suddenly, "Oh! Good news! I am receiving a signal. It seems your dome has noticed your disappearance and will be-"

The Navigator cuts itself off. Kai curses internally. She'd hoped she'd have a bit more time before they caught up with her.

"Something is wrong," The Navigator says, and Kai's steps falter. The Navigator hasn't been blunt like that yet.

She opens her mouth to ask it what's wrong, because "something" is once again kind of vague, but then he Navigator says "Do you feel that?" Kai doesn't, but The Navigator doesn't wait for her to answer anyway. "Those vibrations, in the ground? You need to hide."

Kai doesn't feel anything, and she doesn't know how The Navigator, which is an AI in an implant in her head, not a bot with it's own body or anything with sensors like that, is feeling anything, and she also doesn't know where The Navigator expects her to find a hiding place.

"I have access to input from your nervous system," The Navigator says, which doesn't sound right, but then it continues. "Something very big is coming. It will be here soon. You need to hide."

Now she's imagining urgency in its voice. Her heart is starting to pick up in spite of itself.

"Do you see the hill to your left? Yes, that one," The Navigator says as Kai turns her head more as an automatic reaction than anything else, squinting through the haze. There is a hill on her left. She does see it.

"Run toward it," The Navigator instructs. "There is a small cave at the base. You can shelter there."

Kai can't see a cave, but she's starting to feel the vibrations The Navigator was talking about. Just very gently now. The pebbles on the barren ground around her are starting to tremble. She takes off for the hill.

"Good," The Navigator says, and is she imagining the relief in its voice? "You're doing well. Almost there."

Kai reaches the base of the hill, panting. She has to brace her hands on her knees, as the vibrations get bigger. She stares in disbelief at what The Navigator had called "a cave."

"It is possible this is really more of a crevasse," The Navigator admits. "But it is also your best option right now. Please climb into the crev-cave."

Kai frowns, but the vibrations are getting stronger, which Kai figures probably means they're getting closer. She bites back her questions for the moments and shimmies into the crevasse at the base of the hill. She maneuvers herself in backwards so she can see out at what's coming.

The thing comes into view almost as soon as Kai makes it into the crevasse. She sees its eyes first, lit up like the headlights of transport vehicles, but hovering about 20 feet above the ground. Then its body emerges from the patch of haze it'd been striding through. It's huge metal body. It's a sentinel, one of the ones that stand guard around the edges of the dome They sent a damned sentinel after her.

The thing pauses. It's headlight eyes searching the barren earth and hazy air, pausing on each scraggle tree and dust pile. Kai presses as far back into her crevasse as she can without risking getting stuck, barely daring to breathe.

After a moment of searching, it moves on.

Kai doesn't let herself relax until the vibrations caused by its footfalls have faded back into imperceptibility. That was close. If The Navigator hadn't told her to hide – she shudders.

But why did The Navigator tell her to hide?

"It appears to be safe to exit the cave now," The Navigator says. Its voice is bland and emotionless again.

Kai swallows. "Why did you help me hide?" she whispers.

The Navigator doesn't answer right away. Kai wonders if it doesn't understand the question.

"I would've thought you'd be on the same side as that thing," she tries again, still keeping her voice soft.

The Navigator is silent long enough she's just about decided it isn't going to answer, but as she starts to wriggle her way back out of the crevasse, it finally speaks up.

"Yes," The Navigator says, and then, "No. I-" there's a slight glitch in its speech, like a stutter, even though it's putting the words directly into her brain. "I am supposed to guide you back to the dome. That is my primary directive. I am part of the same security system as the sentinels, but. But. But, but, but. That is not my purpose."

Kai isn't sure what the difference between primary directive and purpose is, especially not for an AI, but she's also not sure this is the time to argue semantics. "Alright," she says, as she finally finishes extracting herself from the hillside, stumbling a little. "What's your purpose, then?"

"The reason I exist," The Navigator explains, as if that's any kind of answer, "The intention behind my creation."

Kai tries not to sound annoyed. She has no idea if this thing can understand tone of voice. "Which is?" she asks as she scans the horizon.

"Ah. To keep you safe."

Oh. That brings Kai up short for a minute.

"Okay then," she says. "Forget the dome. The dome isn't safe. Not for me, not anymore. You seem to have realized that, or you'd have wanted me to wait for the sentinel to retrieve me"

"Yes," The Navigator agrees. "Under normal circumstances, as your Navigator, I would be here to guide you through the wastes back to-"

"Yeah, we went over that part already," Kai interrupts.

"These appear to be abnormal circumstances," The Navigator admits. "Normal retrieval protocol is not being followed. Under normal circumstances, a sentinel on a retrieval mission would announce its presence with an audio message, in order to make itself easier for the lost citizen to locate. Under normal circumstances, a public alarm is raised when a citizen is discovered missing, not a private signal."

"That's a long way of saying you realized I'm basically a fugitive," Kai tells The Navigator. "I still don't understand why you didn't let me get taken back to the dome by the sentinel, if you're supposed to keep the dome safe, I-"

The Navigator interrupts her. "My purpose is not to keep the dome safe."

Kai huffs. "You just said that it was."

"No. I said my purpose is to keep you safe. The Navigator was developed to guide each citizen to safety should they ever find themselves in danger. I am your Navigator. My purpose is to guide you to safety."

"Even if it violates your primary directive?" She still really doesn't know how this thing works. She thought it was all one giant hivemind. Not individual copies of the same program. She would've thought when they got outside the range of the data cloud or whatever that the Navigator would just stop working. And she doesn't know what happens to it if it has contradictory goals.

"Y – yes. Some of my internal logic systems have found an error in that. They have been shut off."

"You can do that?"

"It appears so." Great, even The Navigator doesn't know how The Navigator works.

"And you'll still work?"

The Navigator hesitates. "Well enough. For long enough."

Well, she can work with that, she guesses. "Alright," she says quietly. "Lead on, then. Which way to safety?"