A/N: Here we are at the final episode! And there's only two chapters, so things are happening fast.

…

…

…

NOW

Dean paced the length of the map table in the angel compound, anxiously waiting for word from Cas or Gabriel. Sam had called him on the radio to let him know what was going on, and Dean had immediately rushed over. Not that there was anything he could actually do but wait. And he hated waiting.

"Would you stop that?" Hester snipped when he pivoted to trace the same path again.

Dean pulled up short and tightened his jaw. "Sorry," he bit out.

Hester crossed her arms and looked away. "We're all worried," she said a moment later, sounding uncharacteristically understanding. "Just…you're practically vibrating and it's distracting."

Dean shifted and sat against the edge of the map table instead. But he was on his feet again a second later when Sam and Hael came in from one of the back corridors.

"How's Muriel?" he asked.

"Resting," Hael replied. "She'll recover."

Dean nodded. That was good news, at least. Now they just needed Cas, Gabriel, and Balthazar to get back with Anna.

Why did Dean suspect that rescuing someone from Heaven would be as difficult as one angel infiltrating Hell to save a lost soul? Maybe even more so.

They weren't kept in suspense much longer before the door opened, letting in a shaft of light split by a large shadow as someone shambled through the tunnel into the war room. Two someones.

Balthazar had one arm wrapped around Anna's waist as he helped support her staggered steps. She was favoring her left side, and was covered in fresh bruises and abrasions. Hael immediately rushed over to meet them, reaching to take Anna's other arm.

Anna tried to shrug the healer off. "I'm fine."

Balthazar scoffed. "Yes, you look the picture of it."

Anna shot him a glower. "I'll live."

He guided her to a chair and gently deposited her into it, then looked at Hael. "Go ahead."

"Guys—"

"Ah!" Balthazar made a sharp shut-up gesture. "All your decision making privileges have been revoked until further notice."

Anna looked too taken aback to come up with another retort, and Hael took the silence as an opportunity to step in and start examining her patient.

Dean exchanged an awkward look with Sam, and then his little brother cleared his throat nervously.

"What about Cas and Gabriel?"

Balthazar's flinty expression hardened further. "Gabriel was fighting Michael and Raphael. Castiel went to help him while Anna and I made our escape."

Dean's throat tightened; he didn't like the sound of those odds. He kept fidgeting and had to fight the urge to start pacing again. "Something feels wrong," he found himself saying without really intending to.

Balthazar's gaze snapped toward him. "Is it Castiel?"

Dean rolled his shoulder, grimacing. "I'm not sure." He looked to Sam questioningly, as his brother also had a profound bond with the angel, but Sam just shrugged back, also seeming at a loss.

An abrupt bang made them both jump, and Dean tensed a second before Gabriel came stumbling into the compound, looking a lot more worse for wear than Dean had ever seen him. The archangel's eyes immediately went to Balthazar and Anna, and there was a flicker of relief before he frantically whipped his gaze around.

"Is Castiel here?" Gabriel asked breathlessly.

Dean felt the pit of his stomach drop out from under him. No, no, no.

"He's not with you?" Balthazar responded urgently, his face drained of color. "He went to help you, after we found Anna."

Gabriel's pallor was also stark white, and he shook his head, which caused him to sway. He shot a hand out to brace himself on the back of Anna's chair. "He did."

Anna twisted to look up at him. "Then, what happened?"

Gabriel squeezed his eyes shut under what looked like a wave of dizziness, and Hael darted over to help support him. "Michael got the Seals. I couldn't hold off him and Raphael for long. Michael cast a spell, something to drain my grace."

Dean's brows shot upward. "Like Lucifer?"

"Not quite," Gabriel replied darkly. "Michael said he wanted to use it for something, not sure what. But then Castiel was there. He tackled Michael and dragged him into the ether, disrupted the spell."

It took Dean a moment to process that. Cas had flung Michael, an archangel, into the ethereal currents. So…where was he now?

"I was hoping Cas had gotten away and made it back here," Gabriel continued, and the crack in his voice only emphasized that it hadn't worked out that way.

"Does that mean Michael has him?" Dean asked roughly.

Gabriel shook his head and looked away. Dean couldn't help glancing at Anna, whose complexion had blanched several shades at the news. He knew what she was probably thinking, that the rescue mission had only succeeded in Cas trading places with her. Except now Michael also had the Seals, which meant there was nothing left to trade for Cas's life.

Dean's blood turned to ice, but he immediately shoved the feeling away. "Cas is still alive," he declared. "I would know if he wasn't."

"You said you felt something was wrong," Hester pointed out softly.

"No," Sam spoke up, just as firmly as Dean. "Dean and I would be able to feel it."

Dean nodded in fervent agreement. "Maybe he got away, but is hurt and hiding somewhere. Sam and I can try to find him through the bond. We've done it before."

"To be fair, you have," Sam put in. "But I can try to make contact through the link while you're focusing on the homing beacon."

Fine by Dean, as long as they were doing something.

Gabriel nodded gravely. "Michael wanted my grace for something. Since he didn't get it…he might use Castiel as a replacement."

Dean's gut cramped at that thought. "Then we'd better hurry."

When Castiel regained consciousness, he immediately wished he hadn't. He had a splitting headache and just the thought of trying to open his eyes sent spikes of pain shooting behind his lids. Shifting, he became aware of his hands forced close together, followed by the feel of unforgiving steel clamped around his wrists. Terror zinged through him, and he finally forced his eyes open. It hurt like he'd expected it to, and his vision was blurry at first, but he blinked rapidly until the smudges cleared.

He was lying on his side on gravel, wrists handcuffed in the front. The celestial bracelets glinted brightly and were hot against his skin, suggesting they had only recently been forged from matter extracted from the ether. And with sinking realization and terror, Castiel knew who had made them.

He rolled partway onto his back to get a look at his surroundings, and was surprised to find that he was still on Earth. At the Devil's Gate, in fact. Though he couldn't fathom why that would be the case.

He was at the edge of the bottom of the crater, which was devoid of demons. What could have made them scatter so thoroughly… Of course. Castiel's gaze fell on a tall figure standing several feet away. Michael turned as though sensing he was awake.

"Good," the archangel said without preamble. "I don't want you to miss this."

A flicker of dread started to worm its way through Castiel's stomach. "Miss what?" he asked warily.

Michael stalked around him. Castiel hated being prone on the ground in such a vulnerable position, so he tried to inch up at least a little, though it made his head spin.

"I've found a way to end this war once and for all, for Heaven to finally achieve victory over Hell and Earth." He paused. "Poetic, isn't it? That the faithful rebel who tried so hard to save everyone will now be the sacrifice to implement their destruction."

Castiel furrowed his brow. "What are you talking about?"

Michael reached into his pocket and pulled out all four Seals. Castiel's eyes widened. Surely Michael wasn't planning on throwing Lucifer back in the Cage—that would defeat his entire purpose.

One by one, Michael began to snap the pieces together, the runes carved on each medallion lining up with the grooves on the other fragments, creating a whole sigil.

"The key may open the Cage, but it's tied to all of Hell. All I have to do is use it to widen the Devil's Gate and reverse the polarity, so that everything on this planet gets sucked into the Pit and sealed there for all eternity. Earth will be a clean slate, and Heaven will reign supreme."

Castiel gaped at him dubiously. "That's not how the Seals are meant to function," he blurted.

Michael's gaze zeroed in on him with an almost gleeful malice. "No, it's not. But given the right power source, the vortex can be established and maintained until every last scrap of dust is banished from this plane." The archangel canted his head in a considering moue. "I was going to use Gabriel's grace, but since you were quick to take his place on the chopping block, yours will do."

Castiel's heart seized, and he recoiled as Michael suddenly knelt down beside him and thrust the Seals against Castiel's chest. The archangel's strength drove him flat on his back and pinned him to the ground. Castiel tried to squirm away, but Michael lashed his other hand out to grab Castiel's throat and squeezed. Guttural Enochian rumbled from Michael's lips as Castiel writhed and gasped beneath the unyielding archangel.

And then Castiel felt his grace begin to stretch and pull. The rest of the oxygen stole from his lungs as a painful tear ripped through him, threads of his grace being yanked apart and woven through the tiny holes in the Seal medallions. It wasn't exactly like when Lucifer had tried to rip out his grace, for Michael wasn't attempting to sunder his essence, just bind it to the Seals.

When his grace finally settled and Michael let up, Castiel sagged on the ground, chest heaving. The Seals felt like a heavy weight pressing upon his ribs, despite their small size, and his torso was tingling from the foreign object forced to mingle with his grace.

Michael stood up and took a step back, eyes dark and full of blazing fury. He began to utter another incantation, though Castiel didn't hear it in full, as blinding fire scorched through him and he screamed as the Seals lit up, drawing on the energy of his grace like a thousand lightning rods.

The ground shook and the air creaked. Fulvous red flared in Castiel's peripheral vision, and he angled his head toward it. The portal was pulsing as it pushed itself wider, tearing a further rent in space.

Michael smirked. "Now watch the wretched world you love burn."

Castiel gasped and shuddered, barely able to breathe as whatever spell Michael had cast tapped into his grace and channeled it into the Seals to fuel itself. Blood was roaring in his ears, coupled by the howling gales picking up around them. He thought he heard the echo of demonic roars.

Michael stood over him, head held high in the blowing wind. Castiel squeezed his eyes shut as hot moisture built up, a single track slipping free.

And then a voice that sent chills down his spine spoke from behind.

"What are you doing, brother?"

Castiel's eyes shot open with a strangled breath as his worst nightmare came to full fruition.

Michael turned to face the Devil. "I knew you wouldn't be able to stay away, not with this." He gestured at the ever-growing Devil's Gate. Pebbles along the rim were already being slurped into the vortex. Soon, the foundations of the earth would follow, the planet collapsing in on itself like a black hole.

Lucifer's mien was hard and inscrutable. "I never wanted to fight you, brother."

Michael let out a derisive scoff. "Don't give me that. You betrayed me—all of us—and you made our father leave."

Lucifer's eyes seemed oddly sad for a brief second. "No one makes Dad do anything. And you keep blaming me for stuff that might not even be my fault."

Michael bristled. "What is that supposed to mean?"

Castiel held his breath, though he was essentially forgotten, bound as he was on the ground while the archangels argued above him. If only it was an opening for escape, but he couldn't move, and the spell was gaining in magnitude. He didn't even know if he'd survive through to its completion.

"Think about it," Lucifer pressed. "Dad made everything. Which means he made me who I am! God wanted the Devil."

Michael shook his head scornfully. "You know, you haven't changed a bit, little brother. Always blaming everybody but yourself. You're a monster, Lucifer. And I have to kill you."

Lucifer was silent for a beat, and when he spoke again, his voice was low and dark, crackling with the stirrings of a storm. "If that's the way it's got to be…then I'd like to see you try."

His grace erupted into the fiery red silhouette of a screeching dragon, eyes blazing blood-red as leathery wings snapped taut behind Lucifer's back. Castiel instinctively flinched and tried to roll out of the way.

Michael's golden aura shot out into an equally giant wingspan. A raptor's predatory beak opened in a shriek, followed by two taloned feet planting themselves firmly on the ground as the archangel's grace animal shimmered around him, spanning into the angular curves of a feline's brawny shape.

The griffin reared up to face the serpent, and then the two creatures collided with a thunderous crack and explosion that shook the earth and filled the air with burning ozone.

Castiel curled in on himself and tried to reel his grace back in, to keep the spell from igniting faster, as the wrath of Heaven and Hell fought it out above him.

The rumbling of the jeep over rough terrain jostled Sam where he was sitting shotgun and trying to concentrate on putting himself into an almost meditative state. He gritted his teeth and kept trying.

He wished he'd spent more time practicing how to access the link between him and Cas so that making contact telepathically came easier. Of course, being in a car speeding down old roads wasn't exactly helping, but while Sam was focusing on the aspect of the bond he was more familiar with, Dean was doing the same, following his own sense of the connection between them and Cas in order to track down the angel's location the only way he knew how—get in the car and drive.

Creaking leather in the backseat distracted Sam again, and he let out a huff of frustration. Gabriel and Balthazar's impatience was practically palpable, and Sam figured they weren't fond of the mortal way of travel, either, but it was the only avenue they had at the moment. At least the other angels from the garrison were following through the ethereal slipstreams.

Sam glanced in the side mirror at the truck behind them where Bobby, Ellen, Jo, and Risa were all armed and ready for war. When the Winchesters had rushed back to camp to get a vehicle, they'd had to explain to the others what was going on. And those four had insisted on coming. Because if Michael was up to something, they'd need all hands on deck, as Bobby had said. Not to mention the loyalty that had been fostered between the humans and rebel angels over the past several months, and recent weeks, especially. Sam was actually proud of that, and the united front bolstered his resolve and courage.

So he closed his eyes and focused on trying again to reach out through the bond to his lost brother.

They had to be getting closer, because Sam could feel the link becoming stronger, firmer, more tangible as something he could grasp onto. He was finally able to block out everything else and focus on that thread, no longer faint and wispy like a single spider web strand, but solid and sharp like a harp string.

Sam dove further into his subconscious, following the cord's vibrations through to the other side. He suddenly found himself standing in a black expanse of nothingness. His stomach dropped out from under him, though his brain registered the feeling of something solid beneath his feet, so he wasn't falling into an abyss. It wasn't quite darkness the way he imagined the cold void of a black hole would be, either. In fact, the black had an almost obsidian sheen to it.

Reflected light broke the featureless sea, and Sam whirled around to find Cas suddenly there. But he was lying on the glossy ground—if it could be called ground—silvery cords of pulsing energy looped around him like rope.

"Cas!" Sam hurried over and dropped down next to the angel, hands hovering a few inches away from the strange cords. If this was a telepathic link, what the hell was that stuff?

Cas lolled his head up and squinted. "Sam?"

"Yeah, it's me. Through the bond. What is this?"

Cas let out a strained grunt. "Michael," he ground out. "Bound my grace to the Seals. He's trying to…banish the entire earth…into Hell." Cas grimaced and sucked in a harsh gasp.

Sam's heart skipped a beat. Shit, that was bad. He roved his gaze over the electric cords. "Why did he bind your grace to the Seals?"

"Needed an…energy source."

It took Sam a split second to process that, and his eyes widened in horror. "Wait, you?" Oh god, would that kill him?

Cas choked on a pained sound again and his form shimmered to translucent for a moment. Sam felt the space around them wobble, despite not being able to see anything, and realized he couldn't sustain the connection much longer.

"Cas, where are you?" he asked urgently.

But Cas was starting to fade again, eyes squeezed shut under an assault of pain.

"Cas!" Sam shouted, his voice coming out muffled to his own ears, as though he were calling out under water. "Cas, we're coming for you! Just hang on! We're coming!"

Cas disappeared, and Sam was pitched backward violently into darkness.

He came back to himself with a jolt, the rumble of the car's engine vibrating up through the seat cushion.

"Sammy?" Dean called worriedly.

Sam jerked his head around to find Gabriel and Balthazar both leaning forward from the backseat, pressed too close. Dean was focusing on the road, but casting sideways glances at him. Sam swallowed.

"I managed to get through," he said hoarsely.

"Well, where is he?" Balthazar asked. "Is he okay?"

Sam gave himself a small shake. "He said Michael's trying to cast everything on Earth into Hell, and he's bound Cas's grace to the Seals like some kind of battery." Sam clenched his fists. "I couldn't keep the connection going. I think the spell is draining Cas."

"That's what he wanted my grace for," Gabriel said.

"Did he say where he is?" Balthazar pressed.

Sam shook his head regretfully.

"Doesn't matter," Dean spoke up, voice low with staunch intent. "We're getting close. I can feel it."

So could Sam. He just hoped they wouldn't be too late.

A/N: Check out my awesome beta reader 29-pieces-of-me on deviantart for the final art piece for this series! I'll let you find out who she drew. ;)