Sam walked back to Lower-City carefully, making sure he wasn't being followed. He slipped down one of the side alleys and into an empty building. The basement door was locked, but he picked the lock quickly, and walked through it into the dark stairwell, pulling the door shut behind him.

The basement was damp and so dark he had to turn his night vision (controlled bursts of rhodopsin) all the way up just to see. He moved through the room slowly, until he saw the telltale crack in the wall he was looking for. He pushed on the brick jutting out of the wall and watched the crack widen, just enough for him to walk through.

After a few dozen feet of rocky tunnel, Sam found another door, rusted and old. It led to one of Lower-City's many abandoned subway stations. He hopped down onto the tracks — long since dead — and walked into the tunnel. When he found the second utility door on the left, he stopped and placed his hand on the deceptively discolored metal. A few seconds later, green light ran along the edge of the door. The light made one complete loop, then another, and faded as the door clicked open. Brady and Ruby were waiting for him on the other side.

Ruby grinned at him. "I knew you'd come back." She stepped back to let Sam in.

"No tracker either. I'm impressed." Brady added, reading over the bio-scan results on his meta-cuff. He flicked the display off and gave Sam an odd look.

Sam followed them down the short hallway and onto the long ramp down. The ramp's tunnels were well-lit, and its drab grey walls felt almost cheerful compared to the oppressive air he'd left behind outside.

"I told you he'd be back." Ruby said to Brady. She looked over her shoulder at Sam and winked at him.

It made something in Sam's stomach flutter, even if he wasn't sure why.

"You did," answered the blond man. Cocking an eyebrow he added, "You didn't tell me he had class eight bio-mods though."

"There's no such thing as class eight." Sam said. "And only Angels have mods over class five. I've never been able to afford anything more than a three.

Ruby smirked. "You're both wrong. They're not mods. Not really."

"You gonna keep being cryptic, or tell me what you know?" Brady scoffed.

"You weren't born a Demon." Ruby said to Sam. "From everything you've told me, the nano-bots I gave you should be the fanciest thing you've got. But that's just not true."

"You mean the ash." Sam said quietly. "Right? I survived the fires of '83, but…something changed me. I don't think I've been fully human since."

"How did they miss you?" Brady asked. "Doctrine says there were no infected survivors."

"Doctrine says a lot of things," Ruby said, laying her palm against the metal door they'd reached. "Very few of them are true."

The door hissed open and they stepped into the med lab — the room where Ruby's nano-bot injection had given Sam the missing part of his leg back.

Brady clapped Sam on the shoulder as he walked past him towards the main room. "Well I'd sure love to get a closer peek at your 'not class eight not really mods' someday. Maybe you could spare a cell sample? Give me a drop or two of your blood next time you cut yourself shaving."

"Uh…" Sam watched Brady leave and turned towards Ruby. "Why is he so interested in my cells?"

Ruby raised her eyebrows at him. "You really don't know, do you?"

Sam shook his head. "I was hoping you'd enlighten me."

"Enlightenment comes from the Angels alone." Ruby quoted Doctrine, tilting her head to the side, brown eyes looking into Sam's. "Do not seek knowledge from those who dwell Below for they have no souls and know not right from wrong."

"So that's a no?" Sam asked, smiling weakly.

"Have you ever gotten a mod replaced?"

"No."

"Have any of the ones you've gotten ever failed?"

"No."

"Not a single one?"

Sam shook his head. "No."

Ruby walked over the the operating table and hopped up onto it, her legs dangling over the side. "When I brought you in here, I hoped you were who I thought you were. Lucifer's been talking about you for a long time."

"He has?" Sam asked. His stomach churned nervously at the memory of Nick's decaying skin and Lucifer's cold eyes.

Ruby nodded. "He told us what you looked like, and he told us you were special. That you were made for him."

"He said the same thing to me." Sam swallowed. "Why? What's so different about me?"

"Sam." Ruby laughed. "You got your mods in Lower-City right?"

"Yeah. Whatever I could afford, whenever I had enough for another." He shrugged his shoulders, self-conscious for some reason.

"That stuff is crap. Usually it fails in a few weeks. A lot of the dumbasses that buy those mods don't even last that long because their brains overload."

"You calling me a dumbass?" Sam asked, smiling weakly.

"Well, you kind of are. What the hell were you doing, wandering around Lower-City after curfew? It's like you wanted to get hit."

"Maybe I did." Sam said quietly. He walked closer to Ruby and sat down on the table next to her.

"Those mods of yours. They're yours now. I mean…they're you. Not just grafted on, or fused, but in you. Your mods are completely integrated. They've grown with you."

Sam stared at her. "That's not…possible."

"Except you know that it is." Ruby smirked. "Come on, Sam. You're a…relatively smart guy."

Sam raised an eyebrow. "Thanks." He sighed. "Okay, I know that something about the way I process mods is different."

"Because…?"

"Because of what happened when we were kids." Sam sighed, remembering. "When the Angels first came to the City in '96 Dad was ecstatic. He was there for the ground-breaking of Machen. He volunteered the second they opened for applicants."

Ruby's eyes narrowed. "A true believer?"

"Hardly." Sam scoffed. "He just wanted to have the best firepower at his disposal. He wanted to kill the Demon that killed Mom. More than anything. It's all he talked about. He used to disappear for weeks at a time tracking down some lead or another. Sometimes he'd come back and tell us he'd taken down a Demon or two — but it wasn't enough."

"He wanted Azazel." Ruby said, frowning.

Sam ran his hand through his hair and continued. "When he joined the Angels, Dad disappeared for three months. I was thirteen."

"Father of the year."

"Dean's four years older than me, and he — he took good care of us. He made sure we had enough to eat and enough clean water. I think we would've been fine…but I got sick." Sam looked down at his hands. "We thought it was just a cold at first, or some kind of flu. I had a high fever and everything hurt."

"It wasn't a virus?" Ruby asked.

Sam shook his head. "I think it was just me…and the ash. Dean tried everything he could to keep the fever down. All the fever reducers he could get a hand on, ice bath, you name it. He had to call the Meds, and by the time they got to us, my fever was 105. They ended up sticking a temp-mod in me, just so I'd survive."

"Did it work?"

Sam nodded. "Yeah. Fever went away, and I felt better in a few hours. I remember Dean telling me to toss the mod into the trash whenever it ejected…but it never did."

Ruby stared at him. "What about the anchor? Temp-mods aren't supposed to be able to slip in all the way."

"The anchor fell off overnight, and by the next morning my skin had just…closed back up. I told Dean what happened, but since we couldn't find a bump or anything under my skin, we figured the whole mod had probably fallen out overnight. We didn't even think about it again until Dad got in the running to be avatar."

"For what Angel?" Ruby asked.

"Michael," Sam said.

Ruby whistled. "Damn. Can't get much higher than that."

"When you apply to be an avatar, you have to undergo a compulsory bio-scan. So does everyone else in your family. They check for anything that might mean you're allied with the Demons, including illegal mods."

"Wait." Ruby shook her head, "You mean your fever reducing temp-mod…"

"It registered as an illegal grade temperature and blood pressure regulator." Sam said.

"Which you could use to manipulate lie-detectors." Ruby mused.

"Dad was disqualified. The Angels told him I was a Demon-sympathizer. Since he was my father and I was still a minor, they held him responsible."

Ruby watched Sam silently, waiting for him to go on.

"Dad…lost it. And Dean — he blamed himself. I tried to explain what happened, but Dad didn't want to hear it. Dean went to join the Angels the next day, trying to make things right. Dad wouldn't talk to me. He wouldn't even look at me. So I left." Sam sniffed, and rubbed at his nose. "I never saw Dad again."

"And Dean?" Ruby asked, smiling weakly.

"He came to see me a lot at first, every time I asked him to. He was worried about me, kept telling me to go back to Dad, but…I just couldn't. Not after what happened." He paused for a few seconds, but forced himself to tell the rest of the story. "Then one day in '99, Dean called me to tell me Dad was dead. He wouldn't even tell me what happened until weeks later. After that, everything changed, and when I went to see him today — " Sam's mouth slammed shut, almost against his will, when he remembered what had happened.

Ruby's smile faded and she turned towards him. "I take it today didn't go as planned?"

Sam shook his head and cracked his knuckles, remembering Zachariah and his smirk, and how cold Dean had been. Every time he'd seen his brother in the last few years it had gotten worse — the distance between them becoming greater and greater until he felt like he was standing on the opposite side of a chasm, trying to talk to somebody who couldn't even see his face.

"But you came back. They let you go, at least. That's more than you can say for most Demons that go into Angel territory."

"Yeah. They let me go." Sam huffed. "Dean nearly had me arrested, and one of his Angel guard dogs tried to rearrange my face." He turned towards Ruby and flicked his eyes up towards hers. "Thanks to your nano-bots, I don't have a scratch on me."

Ruby patted Sam gently on the knee. "Don't mention it. It's the least I can do for — "

A horrifically loud alarm went off, and Sam covered his ears, turning towards Ruby in confusion. She shook her head, slid off the table and ran for the door to the server room. Sam followed her. A Demon he hadn't been introduced to ran past them, holding Nick (who looked not just unconscious, but practically dead) and stopped short of the door to Lucifer's room. He lifted Nick's hand up and held it against the door until it opened. The two slipped into the small room and a few moments later the Demon came back out alone.

"Lucifer," Sam heard himself say. He turned back to Ruby and asked, "What's going on?"

"Seraph." Ruby said, her eyes wide with fear. "Right above us."

Seraphim were the Angels' favorite war-machines. Huge mechs, armed with every weapon they had in their arsenal. An average Seraph had enough firepower to flatten ten City blocks.

"What do we do?" Sam asked.

"Fight." Brady said, throwing a laser-rifle at Sam. "They might be Angelic, but they're made of metal. They can break, just like everything else. Go for the leg joints and when the eye opens, aim right for the center. Follow our lead. Don't die." He turned away from Sam and Ruby and crossed the room, heading back to one of the open weapons lockers.

"What about — " Sam looked at all the servers around them. "Are they here for Lucifer?"

Ruby shook her head. "No. They haven't come to our streets like this in years." She grabbed a rifle from the locker closest to her and ran after the other Demons.

Sam swallowed, wondering why he felt guilty. He hadn't been followed. He was sure of it. He looked down at his rifle, then back towards Ruby and followed her outside.

The sky was on fire.

Sam couldn't even see the Seraph at first. All his combat mods were up and running, throwing his senses into overdrive. He forced his hearing back down, trying to quiet the deafening noise of the mech plowing through Lower-City's old buildings. He took cover behind an uneven chunk of wall, crouching down right next to Ruby.

The Demons had taken position in a rough semi-circle, and all their weapons were aimed slightly upwards, angled towards the direction of the noise. Sam had to move nearly two feet to the right before he saw it. The empty husk of a long-abandoned high-rise shuddered and collapsed a few blocks away. The Seraph — enormous, metallic, and humanoid (only in the roughest sense of the word), rounded the corner moving closer to them, holding it's huge arm out wide. It sliced through the other buildings around it — taking them down as easily as a scythe reaping wheat.

Sam looked through the scope of his rifle, trying to get a feel for the weapon. 'Aim for the leg joints. Aim for the eye when it's open.' He focused on the Seraph's head, hoping it would face him.

All the Demons around him waited until the mech knocked down the last building in its path and then opened fire, hitting the mech's legs in force. It seemed unaffected at first, but finally staggered to a halt. It seemed to sink to the right as its lower leg started to fold in on itself.

The massive head of the Seraph turned towards them. Sam looked through his scope, and shifted position again until he could see the center of the mechanical iris. There was a flicker of light around the eye as energy gathered behind it. Distantly, Sam thought he heard someone shouting his name, but he was too focused on the Seraph's eye to respond.

Sam hit the trigger the second the iris started to open, but was instantly blinded by the light pouring out of it. He felt himself fall as something hot and sharp cut through his stomach. He rolled onto his side, thankful that his pain-dampeners were still working.

Meg's voice cut through the noise of the battle, yelling, "Ruby! Get your stray back inside before he bleeds out!"

Sam wanted to protest that he'd be fine if they just gave him a minute. He was sure the nano-bots were rushing to fix the injury already. When he looked down at his stomach he could see right through it. There was a neat, perfectly circular section of him that had been cut out. He reached his hand towards the hole and felt Ruby slip her arm under his head, just before everything went black.

"We have to stop meeting like this."

Ruby's voice brought Sam back from the blissful nothingness he'd been floating in, and when he opened his eyes he saw her looking back down at him with worry. "Did you save my life again?" he asked. His voice sounded as tired as he felt.

"Seems to be my calling." Ruby said. "How do you feel?"

Sam had to think about the question for a few seconds, and then peered down to look at himself. He was lying on a cot or a chair of some sort. It didn't feel cold, like the metal surface of an operating table. The shirt he'd been wearing was in tatters, but his body looked fine. He ran his hand from his chest down his stomach just to make sure he wasn't seeing things. He could have sworn there'd been a hole in his torso the last time he'd checked. There were tubes running into his legs, thick needles stuck into the femoral arteries. "Better, I think. What happened?"

"You got hit, hot-shot. We told you to duck, but apparently landing a shot inside the iris was more important to you than your intestines."

Sam remembered the Seraph's eye opening and the blinding light that poured out of it. "Did I get it?"

Ruby cocked her head to the side and smirked. "Well you nicked it. You took out part of the shutter. Helped Meg get the bullseye. Brady and I took out the legs and after that it was easy."

"Everybody's okay?"

"Almost everybody."

"Who did we lose?" Sam asked.

Ruby turned to look over her shoulder and took a step back from Sam so he could see.

Sam hadn't even noticed until that moment what room they were in and where he was lying. "Is that…Nick?" he asked.

"What's left of him." Ruby chewed on her lip. "Lucifer did his best to protect us from down here, but there's only so much he can do remotely. We still have about a dozen operational defense arrays up there he can tap into, but trying to get the Seraph in range of them is damn tricky."

Nick's body looked withered — like it had collapsed in on itself. He was charred in places, skin completely blackened. Sam looked towards the man's head and saw the white glint of bone where his chin should have been.

"We owe Nick a lot." Ruby said, and walked towards the charred corpse. She stroked what little hair the man had left, and placed her hand against the wall behind him. A section of the wall lifted up three feet, and the table Nick was lying on retracted. The wall sealed shut again, like Nick had never been there to begin with.

Sam swallowed back the bile in his throat and asked, "Why are we in Lucifer's room?"

"Because he's one hell of a doctor." Ruby smiled at Sam as she moved back towards him.

"He healed me?"

"Yup."

"What about the nano-bots? Wouldn't they have — "

"The Seraph's gaze knocks nano-bots out of commission for about ten minutes. I'm pretty sure you wouldn't have made it past minute three." Ruby ran her fingers down Sam's cheek and then turned towards the door. "He wants to talk to you, when you're ready."

The door slid open, and Sam was alone.