A/N: An author's note on the things I've been researching in re: Charon's probable psychology would take up too much space here. I'm adding to the bottom of the lore section before Ch. 1 instead.

I'm not sure why S&M clothing fans have to be chaotic evil in video games, particularly when the lighter forms are so common and popular among "normal" RL folks that they can barely be considered a paraphilia. I guess someone at BethSoft thought it wouldn't fit the vibe if that one lady in Megaton walked up to you wearing a mohawk, a spiky bandoleer and a steel colander over each boob going, "We saved our money and got you this gift. Thanks for doing what you do."

13

Xen paused inside the chainlink door for a moment, letting her naked eyes adjust to the lower light behind her goggles. Nothing seemed to have changed. There was still a red Nuka-Cola machine amid the piles of dirt and debris, fizzling and sparking. She moved down the slope toward the main platform. She thought for a second that they'd already lost Charon, but when she looked over her shoulder, he was still there. His footsteps had become nearly silent, and his leather garments were worn enough that they didn't creak when he moved. He was looking around, but he hadn't drawn the shotgun.

She stopped at the broad doorway to allow Changeling past her. The packbot hovered over to the left escalator and waited. Xen followed her down, feeling the warmth of Charon's large body as he came after. Changeling led them to one of the side tunnels. The hulk of an old train occupied the center track. The corpse of the machine was long, leaving less room to walk, and the ground was uneven. Xen had to look mostly at her feet to avoid impaling herself on one of the protruding bits of sharp glass or rebar. She spared a glance for their forward trail as often as she could, watching for radiation or heat. If there was a rogue bot in the tunnel anywhere, Changeling would be better equipped to detect it than she would, of course. I can't detect electromagnetic radiation from a heatless energy source. Maybe my third contributor could.

At this thought, she felt an old pang of loss. She'd never known him, not even his name. And surely his people would have given him a real name, not a numeric designation like hers. What parts of her were really his? Surely there must be something beyond the purely physical disadvantages and the insufficiently compensatory bonus to her vision (something likely to be equaled or outdone by any robot with a decent sensor suite). Had he argued with the computer of his ship? Had his own people (she would never know their name for themselves) thought of him as stubborn, or loyal, or intelligent, or thoughtful? Had he been clever at fixing things with his long-fingered green hands?

But she told herself, as she had since she was eleven, that if he had survived she would not exist. No creature would volunteer to have parts of themselves stripped out and shoved almost randomly into a genome alien to them. No parent would condone the agonies those earlier hybrids had suffered in their brief and awful lives.

Here she chided herself for being sentimental. The Doctors had condoned those things, and they were her parents. More than he was.

I exist because he is dead. Therefore I must learn what I can in the only way available to me, she thought, reminding herself again of the inevitable conclusion. And then, when I have learned all that I can, I will decide what I'm going to be.

The train seemed unbelievably long as she crept through the echoing silence of the tunnel behind Changeling. Gradually she became aware of background noise – the crackle and hum of electricity through old wires, the gurgle of distant plumbing, and a gravel voice muttering very softly behind her. Xen glanced briefly back at Charon. His lips were moving, but the level of sound was so low she couldn't make out most of the words. He was still looking all around them with no sign of immediate alarm, so she assumed it wasn't to do with anything currently happening.

Then they rounded a gentle curve in the tunnel, and the end of the train came into view. It was jackknifed sideways in the tunnel so that it blocked the way forward. Just before the blockage was a door in the cement wall. A blue light hung above it, rotating rapidly so that it cast an irregular light on the dead train and the warped and dusty sidewalk.

The door was open. It was dark inside, and Xen felt the heat from living bodies.

Changeling slowed to a stop in front of her. Behind her, she heard Charon murmur,

"Dis place is not safe."

"Affirmative for heat signatures," Changeling vocalized quietly.

"I count four," Xen whispered. "Human-sized. No rads, so they're not Ghouls - "

She stopped, startled, as Charon brushed past. He padded toward the doorway in his leather boots, shotgun in hand.

"We don't know that they're hostile!" she hissed at Changeling.

"Apparently one of us does," said the robot.

"Found you," said Charon. He raised the shotgun and fired it into the dark doorway. One of the heat signatures changed position abruptly, and the scream that followed was obscenely loud in the echoing tunnel. Xen started forward, but the robot blocked her path, spreading out her arms to take up as much space as possible with the dangling cargo net. Charon vanished into the doorway.

"No, Xen," said Changeling. "It's too dangerous. If they're not hostile, you can't save them. And if they are, you'll be in his way. Wait."

The shotgun boomed again. Then she heard a scuffle of feet and swearing in a human voice:

"Fuck. He's got a knife, don't get - " There was another scream, then a wet gurgling noise that quickly trailed off. Then it was quiet. Xen stared at the wall, watching four horizontal heat signatures rapidly cooling toward the temperature of the cold concrete. One still stood, tall and implacable. As she watched it faded slowly.

"It's over," she said. "Let me go."

Changeling pulled her arms in and edged slightly to one side. Xen ran past her to the doorway.

"Charon?" she said.

The Ghoul wasn't there. An open door to the next room suggested he had moved on, but if so he had gone far enough that she couldn't perceive his heat signature any more.

A dead man lay in front of her on the floor. He was definitely dead. Even without the change in temperature he was already undergoing, the hole in the middle of his chest would've been a clue. Reflective crimson eyes stared blindly at the ceiling beneath his half-shaven head. He'd been wearing an odd arrangement of leather straps and metal bits, dirty and tarnished but still very definite.

The smell didn't catch her by surprise this time, though it was worse than before. She tried not to breathe through her nose. Almost against her will, she turned to look at the other bodies in the dark little room. One of them had a splatter on the dirty tile floor where her head had been. It was clear from her revealing outfit that she had been female. One had a deep slash across his throat. The last had been cut across his chest and belly five or six times. She could wish she had read less about human anatomy, or she might not be able to identify the pink bulge of intestine. There was a litter of bladed weapons on the floor, one baseball bat, and one pistol. Apparently they'd never gotten a shot off.

Xen tried and failed to match up this carnage with the amount of time Charon had been alone with the Raiders. And they must be Raiders. Ordinary humans didn't have eyes like that, and the aggressive, perverse clothing they wore was what Tori had described to her. If you see them first, run away as fast as you can. And be sure you do see them first.

Many such groups are cannibalistic, Bunni told her. Watch for human remains used as decoration. Sometimes these will be visible from a distance.

Something had been hung on the wall on the other side of the room. Xen walked around the bodies toward it. It was the same temperature as its surroundings, so at first glance she had taken it for something that belonged there. As she came closer ordinary vision resolved the shape out of the darkness.

That did it. Xen ran to the nearest desk, jerked open a drawer, and noisily threw up everything she had eaten for breakfast. From the corner of her eye, she saw Changeling enter the room. The robot's sensor did a quick scan, flickering over the four bodies on the floor and the headless, armless, legless thing nailed to the wall.

It had sounded so clinical when Bunni said it. For some reason the words human remains had conjured up the two Doctors in their field stations, clean and frozen forever in time. She could not have imagined anything like this. Xen wanted very badly to leave the room behind, to forget everything in it. She looked around as she wiped her mouth, but could find no heat sign or radiation from the next chamber on.

"Changeling, see what's in the next room," she said.

The robot glided over to the doorway.

"There is a kitchen area," she said. "No further organic beings or parts. I have infrared readings consistent with Charon's from the room beyond it."

"All right." Xen snatched up a water bottle to rinse the sour taste from her mouth and followed Changeling into the kitchenette. There was a refrigerator, a little table with a chair, and a dirty countertop covered with empty bottles, cold cigarette butts, and a kitchen knife with the end broken off. There were strange-looking apparati on the table. One looked vaguely like a reflex hammer or an old inhaler. One was clearly a needle, but there were canisters duct-taped to either side of it. Only the half-spilled bottle of pills looked familiar. The word BUFFOUT was neatly lettered on the side.

Chems, Xen recognized. She left them alone. All of the Raiders had looked very dirty even discounting the gore. Who knew what diseases they might have?

Then she caught sight of Charon through the doorless entry to the next room. The Ghoul squatted beside the body of a woman as he wiped the knife blade on a slightly cleaner area of her clothing. Her head was turned away, so Xen could only see part of the long slice that had severed all the major blood vessels in her neck. She must have died without a sound. The puddle of blood was still spreading away from her. Blood pumping from the hole in Dr. Graber's neck...

"Xen," said Changeling's voice. Xen shook her head, then realized her hands were covering her face. She lowered them slowly. They were shaking. Charon watched her with his head slightly on one side, as if he were puzzled by her.

"I – they - " She gathered herself forcibly, clenching her hands into fists. "Charon. Are you injured?"

"No," said Charon.

"Was that all of them?"

"Yes," said Charon. He enunciated carefully. "The tunnel is clear also." Xen looked around the room, avoiding the body. It was another set of cubicles with yet another open door in the far wall. This one appeared to lead back out into the Metro.

"I can only reiterate the threat level represented by this person," said Changeling. Xen turned slowly to look at the packbot. The sensor blinked impassively back at her.

"You mean because he just killed five people in less than two minutes?" Xen asked softly.

"Affirmative," said Changeling.

"Could you have done that, Changeling?" Xen asked. "Without damage?"

The robot hummed for a second. "Possibly. Had I been given the opportunity, I would have recommended we detour around them."

"Possibly?" Xen said. "I built your chassis specifically for the purpose of keeping me safe. My information was clearly incomplete." A hysterical giggle rose in her throat. She choked it off with an effort. "I think Charon has proven his usefulness. Or is this just another proof that he could kill you? Is that your problem?"

"In effect," said Changeling. "Yes."

"Then let me solve it for you," Xen said. "Scan for radiation only, this room only."

"Scan negative."

"Now scan infrared."

"Results are consistent with the presence of yourself and the Ghoul."

"Now activate your sensor's emergency shutoff," Xen said.

"Your order conflicts with a primary directive. Rendering myself blind represents a direct threat to your wellbeing. Overriding." Changeling made a soft click. "I am detecting an internal error."

"Yes, why don't you take a look at that?" Xen said.

"Creator override recognized," Changeling said.

"Establish new primary directive: Follow my orders."

"New directive established," said Changeling.

"Establish subordinate primary directives: Protect me. Protect Charon. Protect yourself."

"New directives established," said Changeling. "How was that possible? I have been carefully scanned for error-based overrides."

"I'll bet you have," said Xen. "It's firmware built into the chassis. I originally put it there in case something went wrong with Camel. Now listen closely. You will refer to Charon solely by name or pronoun, not as the Ghoul. Is that understood?"

"Affirmative. I can assure you that this gesture will be wasted on him, however. It is questionable whether he will even perceive it."

"There's no point in threatening you, because you don't feel fear," Xen said. "But I will tell you this. Any attempt at physical coercion on your part should no longer be possible. If the attempts at verbal manipulation continue, however, I will use another override in my possession, dump your AI, and use your lobotomized chassis as a pack animal. Acknowledge."

"Acknowledged," said Changeling.

"Let's go," said Xen.