Disclaimer: I disclaim nothing! Except all of the stuff that doesn't belong to me.

Warnings: This chapter contains a significant amount of pretty graphic violence. It is the climax of this story and as such, it includes two big fights, each of which ends in a particularly gut-wrenching way. Most of you probably will have no problem with this, especially if you've read the rest of this story, but if you don't like icky bloody violence, this may not be the chapter (or fic, come to think of it) for you.

Thanks: To every reviewer, and more importantly to the infinitely patient and excellent Ophelia, without whose efforts this story would be far less enjoyable.

Note: You people are getting this chapter a day early because I'm a nice guy (well, not really, but whatever), and that last cliffhanger was pretty brutal. This does mean, however, that you will have to wait about a week for chapter 8.

Chapter 7: Crossing the Line

Sam had seen this expression directed at him only once before. It had been a shape-shifter, in Dean's form. It had horrified him then in a way that he still could not find the words to express. This was infinitely worse. This was indisputably his brother.

And his brother was about to try to kill him.

"Dean, get a grip man, that thing is controlling you." Sam tried, his voice betraying his rapidly mounting fear as he and Dean circled each other. That was not precisely true. Sam knew more about Ansius than anyone else could hope to. He knew Ansius wasn't directly controlling Dean's actions. He knew that everything Dean was doing was rooted in some part of himself that Ansius had disinhibited. Ansius had removed barriers like morality, rationality, and loyalty. In so doing, he had freed portions of Dean's subconscious and given them control.

As much as this changed him he was still, fundamentally, Dean.

Sam knew better than anyone that selective disinhibition of parts of the subconscious was a powerful means of mind control, and an easy way to induce a violent psychotic break. That did not make this easy. He now understood why Dean refused to talk about what had happened in the Asylum, when their roles had been reversed.

"You've got to die, Sammy. You're not natural." Dean's voice was fatherly, authoritative. "And I know that you didn't mean to kill Mom, and Jess, but they still died because of you."

The words hit Sam like a brass-knuckled fist to the stomach. He tried not to show how much it hurt, but he knew Dean could see it all the same.

"You don't believe that." He whispered, steeling himself against tears.

"How can I not?" Dean demanded. "They died the exact same way, above your bed and the only thing they had in common was you."

"Stop, Dean. Please." Sam pleaded, choking back a sob. This was an attack against which he had no defense. Sam had never insulated himself from the guilt he felt about his mother and girlfriend. It had been Dean who had protected him from it, convinced him of his own innocence every time he thought to fault himself. So Dean knew better than anyone how to smash that wall down. Cold empiricism: the only thing they had in common was you. Sam was the only, or at least, by far the best explanation.

"People with powers like yours don't belong in the world." Dean continued, his voice apologetic. "It's not your fault that you're dangerous, Sammy. You were born that way. And I know it tears you up inside to think of all the pain you've caused—because you're a good person."

The most twisted thing about it was that Dean's voice conveyed love. "I know you want it to stop. I do too. It hurts me to see you in pain. So let's end it. Right here. Right now."

Even now, Dean loved him and wanted what was best for him. It was death. It was death that was best for him. Death that would stop the pain Sam felt and Dean hated to see. It was all so reasonable. So simple. So obvious. Sam's whole body trembled, fighting against the possibility that this Dean was right, and the other was wrong. That by stripping away Dean's excuses, Ansius had left him with the truth.

"Come here, and let me do this quick. I promise you won't feel a thing." Dean reached a tentative hand into the intervening space.

Sam almost took it. It wasn't for his own sake that he didn't. Sam knew what it meant that Ansius was influencing his brother. He knew what Ansius was trying to show him. Trying to get him to do.

And he knew what it would cost Dean if he didn't stop him.

There was a dark pleasure in the hunt. Understanding it required the recognition that the motivation to provide and protect was no more powerful than the motivation to kill for the pleasure of it. Dean felt pleasure in the hunt because it allowed him, through acts of violence against things he associated with the loss of his mother, some measure of revenge.

What kept him human—what kept him humane—was that there was a line he would not cross. Dean could kill a human being he thought dangerous. He hadn't had to yet, but he could. The line wasn't even at innocence; he'd been willing to kill Roy LeGrange before they'd even had all the answers. For Dean, the line was his brother. Dean might sacrifice the world to destroy the thing that killed his mother. He would sacrifice his own life and soul. He would never sacrifice Sam.

For Ansius it had been his sister. He had become a servant of evil the moment he killed her. Now Ansius wanted a mortal body; one that he could easily inhabit so that he could exist perpetually in this world, but he was constrained by mystic law. He was unable to simply possess a mortal being. For Ansius to possess Dean, he needed Dean to cross the very same line that he himself had. He needed Dean to kill Sam.

Sam struggled to get control of himself. It wasn't easy. A large and growing part of him had heard everything that Dean had said, and believed it all. That didn't change Sam's love for his brother though, and Sam would not allow his death to facilitate the invasion of Dean's body by an undying monster.

He had to survive this, if only to save his brother's soul.

Fear, guilt and regret were not helpful. He was going to have to fight his brother, and he was going to have to win. Luckily, the Winchesters were well-practiced at converting unresolved pain into anger, and anger was quite helpful indeed.

Sam leveled his grey-green eyes at Dean.

"I'm not going to let you kill me." Sam growled.

"I understand. You're afraid. You need help." Dean cooed, as if speaking to a four-year old. "I'll help you Sammy."

"God I'm going to enjoy kicking your ass." Sam said under his breath, bringing his hands up.

----------

Neither man was armed. Sam had a dagger tucked in his belt, and a backup strapped to his right calf, but he wasn't about to use either on his brother. Dean looked drained from his captivity, while Sam was fully recovered from his injuries. He was fresher, and he was fighting for his life. That didn't mean Sam was confident. He'd never been in a knock-down, drag-out 'two-men enter one-man leaves' type fight with Dean. He'd always suspected Dean had held back when sparring. Held back even when they fought for real, over the things brothers fight about. Even then, Dean had usually kicked his ass. Still, he'd been younger then, and the smaller of the two. Now he had the size advantage.

Dean threw the first punch and Sam deflected it with his left arm, countering with a body-punch that Dean didn't bother to block. A feint and a kick to the shin sent pain shooting up Sam's leg. He grimaced and stumbled, but stayed standing, throwing an elbow at Dean's jaw.

Dean dodged left, using the opening to hit Sam with a left/right combo in the stomach, eliciting a gasp from Sam as some of the air was pushed out of his lungs. Sam backed out so he could take a breath. Dean ducked in to prevent it, throwing a thunderous right followed by a powerful front kick. The punch missed and the kick's force was blunted by Sam's backward momentum. Still, it sent him reeling back into the wooden wall. He braced himself and got back into fighting position.

This was not good.

He looked up at Dean, whose expression still read like a man sorrowfully being forced to put down the family dog.

"The sooner you accept this, the less I'll have to hurt you Sammy."

"It's Sam, asshole." He leapt forward, throwing a right heel kick that narrowly missed Dean's head. Dean dodged back and Sam had the initiative. Focusing his rage, Sam flew into a frenzy. He threw punch after angry punch, kick after furious kick. Dean was pushed back under the pressure of his brother's advance.

Sam tried to keep his brother on the defensive, but it was exhausting. Dean seemed almost too prescient; he artfully avoided the worst of the blows, getting in a few hits of his own while easily avoiding significant injury.

Sam threw a spinning back kick and Dean grabbed his leg. He shoved Sam backwards. Sam barely managed to stay on his feet and quickly wished he hadn't made the effort as Dean connected with a right turning kick to his left cheekbone. Dean advanced slowly and surely, anticipating Sam's every step and making headway with brutal counterattacks.

Sam could feel himself losing the fight. It terrified him. Every move was turned against him. Every hit he registered cost him several in return. He was battered and bruised and seeing stars. He must have taken dozens of vicious hits to the face and body before he found his back against the wall again.

He threw his last meaningful punch with his right. Dean caught it and twisted, eliciting a yelp from Sam as he was shoved sidelong into the hardwood wall. Maintaining his hold on Sam's arm, Dean used the opening to deliver three devastating side kicks to Sam's torso. Trapped between Dean's foot and the heavy oak, the only place the force could go was into compressing Sam's ribcage. Both of them felt and heard the cracks as several of Sam's ribs broke under the pressure. Sam cried out in pain, and only cried louder as Dean continued to twist his arm, forcing the shoulder out of its socket and inducing a spiral fracture just below the elbow.

Then Dean finally let Sam fall.

Sam tried to get up by bracing against the wall, but could not overcome the pain. He whimpered as he fell again. He found he was having trouble breathing. That probably meant a punctured lung. He could taste blood in the back of his mouth, which meant internal bleeding.

He was dying, and Dean wasn't going to save him.

Dean crouched down next to him and Sam tried to back away, but a hand on his injured shoulder forced his compliance. Sam tried to keep from crying.

"Sammy, you're only hurting yourself." He moved around to Sam's front, and kneeled, straddling Sam's legs. Sam's back was against the wall and his right arm hung uselessly at his side. Sam reached over with his left to grab the dagger in his belt, hoping he could at least hold Dean off until he came to his senses. Dean was far too quick, catching his hand and pinning it to the wall above his head. "It's over."

Ansius walked out of the shadows behind Dean. His face was grimly satisfied.

"Well done, human." He commended. "Now take his dagger and finish him. Stab him through the very wound I gave him." Dean took the dagger off of Sam's belt with his left hand, as Sam tried pathetically to resist.

Dean looked into Sam's eyes with deadly earnestness.

"Dean, you've got to fight this. He wants your body. He's twisting your mind." Sam babbled as fear threatened to overwhelm him. "Please…" He said, beginning to cry. He very nearly started begging for his life. Dean leaned down and kissed his forehead.

Dean plunged the dagger into Sam through the scar Ansius had made, all the way through his body and an inch or so into the wooden wall behind.

Sam's eyes widened at the pain, surprised even now that it was his brother doing this. That was it. There was nothing more he could do to save Dean. He had been too weak. Sam looked up at his brother through dimming eyes and whispered.

"I'm sorry."

----------

As Ansius released his psychic hold, Dean looked down at his brother, and nearly screamed as realization gripped him. He fought with every part of himself to retain control as his greatest nightmare played out before him. Ignoring Ansius completely he stripped off his over-shirt, and, ripping it in half, made two bandages. He left the dagger in Sam's body, knowing that it might be all that was preventing his brother from bleeding out, and staunched the entry and exit wounds as best he could with a bandage each. He fastened them there with his belt.

He snaked his left hand up Sam's right calf to find the backup dagger he knew Sam was carrying. With the weapon in hand he rose to face the demon.

"He's still dying." Ansius knifed, his eyes betraying sadistic glee. "And when he does, your body will be mine."

Dean stared at the demon coldly. Even having touched the relic, he was no match for this creature with only a dagger in his hand. He subtly surveyed the room for another weapon.

"I suppose you're wondering why I released you at all." The demon continued, arrogantly turning his back on Dean as he needlessly exposited. "I wanted to fight you one more time before I destroyed your soul and took your shell as my own. The wound your brother is bleeding from will give us a few minutes' time."

Ansius turned back around, a gleaming cross-hilted longsword in his left hand. "I believe this is your weapon of choice?" He laid it on the floor and pushed it over. Dean stopped it with his boot, reached down, and picked it up.

This thing was going to regret giving him a weapon.

----------

Dean deflected a thrust and made the demon pay for it with a push kick to the midsection. Ansius fell back several steps and brought his sword up. Dean took a step in and Ansius backed away, maintaining the distance between them, the demon's expression one of genuine surprise. It was as if he had been a demon for so long he didn't remember pain. Dean would enjoy instructing him on the subject.

Ansius' face changed rapidly from surprise to excitement. He was going to get the challenge he had desired for centuries. After that, he would have a new mortal body with which to rid the world of every unnatural thing. He unhooked his regal purple cloak and let it billow to the ground. He abandoned his aristocratic posture, shifting his weight to the balls of his feet and dropping into an athletic stance that mirrored Dean's.

Dean glared back at him, his green eyes betraying raw, honest hatred. Dean brought his weapons around and up, stretching his arms through the full range of motion. He straightened his right arm, pointing the sword blade directly at Ansius before bringing it down into fighting position.

This was about to end.

They stared at each other across the space. Dean knew that time was limited. That Sam was slipping away. Ansius was going to make him move first. So he did.

Dean leapt forward, thrusting with his longsword in what seemed to be anything but a feint. Ansius was not fooled, sidestepping easily and bringing his sword out in a short arc to deflect the real attack, an upward thrust with the dagger. The demon recovered initiative faster, almost too fast, and Dean fell back with a cut on his chest, his dodge just fast enough to avoid more grievous injury.

"Come now. You can't have thought that would work."

"Get 'em in while you can. You won't be talkin' for much longer." Dean growled, rage boiling over into his voice. He did not doubt himself. This latest injury was just another affront to be rectified, another crime for which Ansius would have to pay.

This time Ansius moved first, bringing his sword around in a long arc that stopped before it reached Dean's sword. He dodged in and under, bringing his sword up and barely missing Dean's throat. A punch to Dean's abdomen sent him reeling before he could connect with his counterstroke. Dean recovered quickly and looked to Ansius.

"Your brother is running out of time." The demon mocked in a worried voice. "Dying from wounds you inflicted."

"You shut your FUCKING mouth!" Dean shouted, charging at Ansius, sword and dagger swinging wildly. Ansius moved in and out, exploiting every hole, every vulnerability, even as Dean pushed him back with a flurry of spiteful blows. Dean kept the pressure on, ignoring the hits, ignoring the pain. Each strike came closer to landing, drove Ansius further back until at last Dean saw his opening and struck with all his might.

But the demon was gone.

Dean took a breath and felt the pain of five newly opened cuts. Even now he could not think of losing. Sam was counting on him. He would not fail his brother again.

"Show yourself you fucking COWARD!" He yelled at the rows of pews.

Pain shot through him as he felt Ansius' sword pierce his right shoulder. He dropped his longsword and it clattered loudly against the granite floor. Behind him, Ansius laughed arrogantly.

"You had a chance, Dean Winchester. If you were stronger you might have stopped me." The demon leaned in close to whisper to him. "My power to heal is in my blood. If you had only defeated me, had only loved your brother a little more, you might have saved his life."

The words were like salt poured into Dean's bleeding wounds. That was what the demon intended. This was about inflicting as much pain as possible. From where Dean stood, he could see his brother slumped against the far wall, impaled by a dagger he himself had driven into him. Despite the distance he could almost hear Sam's labored breathing, almost feel his heart slowing. Dean almost collapsed under the weight of his own desperation.

From somewhere within him, deep and primal and near forgotten, from somewhere beyond good and evil, beyond the reach of even the mightiest demon, came a memory of his own words. A promise he'd made to his brother.

As long as I'm around, nothing bad is going to happen to you.

Dean couldn't give up on Sam. It wasn't in his nature. His despair turned to rage and determination as he realized that he could still save his brother. If he had no strength left in him then he would have to conjure it from nothing. He would not just allow this to happen.

Ansius left his sword in Dean's shoulder just a moment too long. It was the demon's last mistake.

With a defiant bellow, Dean threw himself backward against one of the square pillars with all his might, pinning Ansius behind him, forcing the demon's sword further into his shoulder. He grunted in pain as he re-gripped his dagger and buried it in Ansius' side, eliciting a howl of pain from his opponent. He pulled it out and drove it in again, and again, and again, through flesh and bone with horrible force, reveling in the demon's cries.

Slowly, Ansius' struggles ceased. That was it. Dean had won.

He forced himself forward and away, trying hard to ignore the nausea-inducing sound of the demon's sword sliding out of his shoulder. Ansius slumped to the floor behind him, sword still gleaming in hand, miraculously bloodless in the warm light of the stained windows. Dean looked across the room at Sam.

The image of his horrifically beaten brother pinned against the wall, dagger through his torso, bandages soaked in blood, was one Dean knew he would never forget, but could not now consider. The demon's blood was Sam's only hope, and he had to drench him in it fast. He grabbed the demon's body by the legs and began to drag it over to his brother.

End Chapter 7