A/N Last Chapter :(


Hope it's good and doesn't disappoint :)

Thank you for your favorites and follows and reviews!

(Also, Merthur moments coming up)

The Catacombs –Nimueh's lair

8:45 PM

Gwen's head ached something terrible when she finally reopened her eyes. She attempted to move, but her arms had been pulled behind her back and shackled to a stone pillar. Glancing to her right, she could see Morgana and Gwaine chained the same way to two other pillars, both now conscious and glaring at Valiant, who stood silently to the side with a hammer in his hand. At his feet were all their grenade belts, the timers now busted.

Her eyes moved to the rest of the room, immediately noticing that the three pillars had been positioned in a semicircle around a nave with a stone alter was set towards the back, behind which was a stained glass window of an angel holding a key. Gwen frowned when she noticed a body lying on the pedestal, but she couldn't make out any details about them from the angle she was sitting. A small movement in her peripheral caught her attention and she turned her head, her stomach instantly twisting into knots.

Merlin sat on his knees between the pillars and the altar in the exact center of the circle. His head and hands were locked in a wooden yoke that was chained to the floor, and something told her that whatever symbols were carved into the wood were put there to prevent him from escaping. His head bobbed as he began to wake up.

"And I looked," Nimueh's voice suddenly rang through the chamber, "and beheld an Angel, and in his hand the key to the bottomless pit..." The dark-haired witch appeared behind the altar, a small book open in her hands and a smug smile on her lips as she looked down at Merlin, now fully awake and glaring at her with hate. "These were the words I heard as a little girl. And now, the door."

She set down the book and walked over to a large stone slab that was to her right. Three small handprints were burned into the marble and outlined with a golden light. "Sent down by the Gods of Chaos so that, at long last, they may enter our world. All that it needs is the key."

"No!" Morgana yelled, pulling against her restraints, but she was silenced by a kick to the stomach, courtesy of Valiant.

"Yes," Nimueh chuckled, her gaze falling on Merlin once again. "You are the Key. The Key of Doom. Tell me, my dear child, what did you think your magic was for? Helping those worthless cockroaches?"

Gwen could see Merlin tense up and his hands clench into fists, but she saw sadness and fear in his eyes. The truth stab into his heart, and her stomach clenched with anger.

"Don't do it, Merlin!" she shouted. "Don't listen to a thing she says! You're better than –"

Valiant swung his hammer into her face, fracturing her cheekbone and making her see stars.

"Shut your mouth." He commanded, turning his attention back to Nimueh.

"Open the locks, my child." She purred, ignoring Gwen's outburst as she sauntered over to where Merlin was chained. She knelt in front of his and placed a hand on his cheek. "Just imagine. A new Eden… for you and for him."

She motioned to the altar, and Gwen stretched her neck up to get a better look at the figure on the table. She gasped.

Arthur was laid out lifeless and pale as a ghost on the altar, still out cold from his episode, with only a ceremonial robe covering his body. She thought about how much he looked like a human sacrifice, and felt sick to her stomach.

Merlin gave Nimueh a defiant stare."No." he growled, his voice full of rage.

Nimueh pursed her lips, looking disappointed but not surprised by the demon's answer. "In exchange for his life, then?"

Merlin's eyes widened and he held his breath, not trusting his voice as he shook his head no. Nimueh sighed.

"Very well." She rose back up and drifted over to stand behind the altar.

"No." Merlin begged, pulling against his restraint, desperately trying to break free. Nimueh ignored his pleas and leaned in close over Arthur's face. A short, whispered spell slipped from her lips and the blond's mouth opened and a blue mist trickled out.

"No, no, no, no, please no…" Merlin was crying now and pulling the chains with every ounce of strength he possessed while Arthur's body convulsed and arched in pain. Finally, the movements stopped and Arthur's body went limp. Nimueh inhaled the blue mist with a grin.

"He is dead." She proclaimed, and something in Merlin's eyes shattered. He crumbled to the floor in agony and a pathetic whimper fell from his lips.

"You bitch!" This time, it was Gwaine who had the outburst, tugging against the chains with his hands out, ready to strangle Nimueh with his bare hands. "I'll kill you!"

A cry of pain sounded from Gwaine's pillar and he was silenced, but Gwen's attention was on the broken demon sobbing in front of them.

"His soul awaits you on the other side, my child." Nimueh continued. "If you want him back, all you have to do is unlock the door…and claim him." She glanced up at the sky. "The eclipse is beginning."

Gwen could see Merlin's inner struggle for an answer, to find a reason to say no, but she knew the moment he dropped his head in defeat what he would say.

"For Arthur." His voice came out in a hoarse whisper. "I'll do it for Arthur."

A triumphant look crossed Nimueh's face and she moved back to kneeling in front of him. "You won't be needing this." Her hand grabbed around Gaius' rosary and snatched it from the boy's wrist before tossing it away. "The symbols etched into the wood around your hands are what have been preventing you from using your magic. They are your name, your true name… Emrys. You must say it. You must become the key."

Merlin took a shaky breath and squeezed his eyes closed. "Emrys."

A shiver ran down Gwen's spine as a golden light engulfed the demon like flames, destroying the yoke and allowing him to stand. His horns extended out until they were at least a foot tall and a golden-red flame settled between them like a crown. A new arrogance and sense of power seemed to take over him, and when Gwen saw his eyes, she knew that this was no longer the Merlin they knew. This was Emrys, the Key of Doom and Prince of Hell.

"Merls! Come on, don't do this!"

"Please listen to us! We're your friends!"

Gwaine and Morgana continued with their screams of protest while Gwen watched pensively, knowing that all the pleading in the world wouldn't get through to him, and that if she wanted to stop him, she had to get loose of her shackles.

She started pulling against her shackles, keeping a cautious eye on Valiant as she worked, but he was too busy watching with awe as Emrys approached the slab and placed his hand on the first marker, sending a beam of crimson light shooting up into the sky.

The pulling was beginning to cut through Gwen's skin and suddenly, an idea came to mind. Using her other hand, she spread the blood from her wrist over her hand and started working it free, the blood making it easier to slip out.

Emrys placed a hand on the second lock and the light grew brighter. Storm clouds began churning overhead.

Gwen had finally pulled her right hand free and begun to work on the other when something on the floor caught her eye. Swinging her foot out, she kicked it closer and stretched out her hand as far she could to grab it.

Nimueh's face lit up as lightning cut across the sky, lighting up the monstrous forms that had begun descending to the Earth. "Yes, now open the final lock!"

"Hey!" Valiant shouted, seeing Gwen pulling her hands loose out of the corner of his eye. He moved to stop her, but Gwaine shot his legs out and wrapped them around the Nazi's ankles, dragging him down to the ground while Morgana brought the heel of her foot down on his face, knocking him unconscious.

Finally freeing her other hand, Gwen stood up and held Gaius' rosary out in front of her.

"Merlin, remember who you are!"

The demon's hand stopped just above the final lock as Merlin battled for control. Seeing her chance, Gwen tossed the rosary in his direction, and he caught it without a second thought.

"You have a choice." She continued, feeling more confident. "Your father gave you that choice. You don't have to do this."

His hand opened slowly and Gwen could see the rosary branding his skin. He brought the other hand away from the slab and began stroking the mark with a thoughtful expression.

Nimueh's expression twisted into one of fury. "Don't listen to her! You don't have a choice! It's your destiny! You must open the door now!"

Merlin opened his hand and a stared at where the cross burnt into his flesh and looked back at Gwen with a smile. Before Nimueh could stop him, he grabbed his horns and, with a roar of pain, snapped them off at the root. The slab shook with energy and the beam of light cut out, sending the monstrous shapes back to the hellhole they came from.

"WHAT HAVE YOU DONE?" Nimueh demanded, pure rage seeping from her. She let out a choked gasp as Merlin rounded on her and drove one of his horns through her gut, anger and loathing filling his face.

"I made a choice." He turned away and, using his magic, freed Gwaine and Morgana from their shackles.

"You will never fulfill your destiny." Nimueh choked out. "You will never know the true extent of your powers."

Merlin shrugged. "I guess I'll just have to find a way to live with that."

"Merlin…" Morgana whispered, looking at the altar behind him. The demon's heart fell to his stomach when he remembered the reason he'd said yes in the first place.

He slowly approached the blond still laid out on the table and placed a hand on his cheek Merlin held back his tears for later as he pressed a kiss on Arthur's forehead and, with the help of some magic, scooped him into his arms and started carrying him away from the horrific lair.

"Child…" He turned again to Nimueh, who sat on the ground with a broad grin on her face. "Look at what you've done…" Merlin gaped as black tendrils slithered under the skin of her face and arms. "You have killed me… a mere mortal… but you have brought forth a God."

To everyone's horror, the witch threw back her head and a group of tentacles forced their way out of her throat.

"Okay, I think we need to run now." Gwaine suggested, running towards the tunnel entrance with the rest of the group not far behind. When they were a few meters down the tunnel, Merlin stopped and put Arthur down on the floor.

"Merlin, what are you doing?" Gwaine asked, coming to a halt a few feet ahead.

"Going back to stop whatever the hell that thing back there was. Gwen," he looked over at his handler. "Keep an eye on him. Please. No matter what, keep him safe. Promise me."

Gwen nodded in agreement. "I promise but… you're going alone?"

Merlin shrugged. "Ah, come on. How big can it be?"

As if answering his question, a tentacle the size of a subway train stretched out down the hall and wrapped around his torso, dragging him back into the catacombs.

The Catacombs

9:34 PM

The beast was huge. It stood at least five stories tall and was at least half that in width. Tentacles sprouted all over its body, which was shaped like a tree trunk with a gaping hole full of fangs at the top.

The beast swung the tentacle holding Merlin in the air and slammed him against the ground again and again until stars appeared in his vision.

"Alright," he grumbled. "I've had about enough of you."

He focused all of his magic into his right hand turning it red hot and pressed it against the beast's thin skin. It roared in pain and Merlin found himself face planting the ground. Sore, but free. He grabbed at the ground to push himself back up, pausing at the feeling of cold metal under his fingers. He lifted his head and grinned.

"Hey, stinky!" He yelled once he was vertical again. He shot some magic bolts at the beast to get its attention and another tentacle wrapped around him, this time bringing him up to the mouth. Merlin squeezed his eyes closed and sighed. "Oh, this is gonna hurt…"

He held up the grenade belt he'd found on the ground and pulled the cable just as the tentacle released him into the mouth.

The Outside Corridor

9:52 PM

A heavy silence fell over the group as they waited for a sign. A sign that said the monster was dead, a sign that said Merlin was alive… something.

Gwaine paced back and forth looking back towards the chamber every few steps to wonder if he should go back and help, while Morgana and Gwen crouched in front of Arthur's lifeless body, trying to find some sign of life, when the silence was broken by an earth-shaking boom that almost brought down the tunnel on them.

They held their breath for a second…

Two seconds…

Three seconds…

And a lanky red figure covered in slime came staggering around the corner. "I got him!" Merlin grinned, earning a sigh of relief from Gwen and a tight hug from Gwaine (who didn't seem to care that he now had monster guts on him).

"Merlin…" He looked down at Morgana, still knelt in front of Arthur, gazing up at him with tear-filled eyes. Merlin's heart stopped in his chest as she answered his unasked question with a shake of her head. "He has no pulse. He's not breathing."

The demon rushed to the blond's side and held him in his arms, brushing a piece of blond hair out of his eyes. Morgana and Gwen moved away and he rested his forehead against Arthur's, praying for one more miracle. Just one.

He didn't even acknowledge when Borden entered the corridor, looking like he'd been wandering through the tunnels for the last few hours.

He pulled Arthur close to his chest and moved his lips up to his ear. The rest of the group watched quietly as Merlin whispered something into his ear, and the air around them briefly lit up gold before fading back.

"M…Merlin…" a faint voice moaned. The others watched in amazement as Arthur lifted his head to look Merlin in the eye. "Merlin." He repeated, stroking his fingers down the demon's cheek.

"I heard your voice… in the darkness…" he whispered. "What did you say?"

Merlin chuckled. "I said, 'Hey, you on the other side. If you know what's good for you, you'll let him go. Because if you don't, I will cross over there for him, and then… you'll wish I hadn't."

Arthur looked at Merlin like he was seeing him for the first time and the blush grew on the demon's face. They leaned in closer to each other and finally, their lips met in a tender, yet passionate kiss. Arthur's skin lit up with gentle fire and deepened it as Merlin put his arms around his neck, pulling him closer.

Gwen looked on, thinking back to Gaius' words to her not even a week ago, and her heart filled with pride at the young demon before her.

What makes a man a man? She thought as the fire grew over Arthur and Merlin, haloing them and casting a warming light over the corridor. Is it his origins? The way he comes to life? Or is it the choices he makes? Maybe it's not in how he starts things, but in how he decides to end them.

A/N Welp, that's the end. I hope it was good. I spent hours staring at this chapter thinking 'Is it good enough? Did I describe everything okay? Did I wrap everything up?'

So, I hope it was satisfactory and that you all enjoyed the story.

I really want to know, if I were to write a sequel, would anyone read it? (It would be based on the second Hellboy movie like how this was based on the first one) So, just you know, let me know :)