WINCING, MERLIN DOUBLED OVER. Blood thumped loudly in his ears and his head pounded. In his bent position, he clasped his hands tightly around his ears and gritted his teeth. He couldn't keep Emrys's memories from flooding his mind as the wall between their worlds came crashing down, and the sudden pour brought him to his knees on several occasions.

An image flashed by of Emrys standing over top of Gaius's bed staring down at the sleeping old man. Emrys didn't speak, but his thought process peaked Merlin's memory. "Soon, Gaius." Emrys had thought. "Not today, but some day soon." The memory cleared and the pain subsided.

Merlin panted, placing his hands on his knees. He couldn't keep the anger that burned within him doused as each new memory came to light. Emrys had killed several people throughout all his years, but in this memory, he had threatened the life of someone very close to Merlin, and he wouldn't let Emrys get away with it.

Clenching his jaw, he trudged forward, getting ever so close to Camelot's walls. "Enjoy your last day on earth, Emrys, because your time is coming." Merlin narrowed his eyes. He knew his inner half could hear him. Emrys had spoken to him several times over the past couple days. "Gaius and I are going to find a way to finally be rid of you."

"Is that so?" Emrys taunted back. Merlin was caught off guard not really expecting a reply. "Tell me, do you really think Gaius is going to find all the ingredients you need in mere seconds? It'll take hours, if not days, to collect everything for a spell that powerful." His voice paused until it came back maliciously. "You really think you can hold on a couple more days?" Merlin swallowed a lump in his throat, and Emrys's laugh echoed off the walls of his brain. "War's coming, Merlin, and you can't stop it. Whether I'm there with Morgana or not, she won't halt her attack for me. Not when we've come so far."

"You're wrong!" Merlin fired back. "Neither you nor Morgana will win. I'll tell Arthur if I have to. He'll stop you."

"Cute," Emrys chuckled. "But I've fought the Prince before and won. And that was without my magic. Imagine what I can do with it. He's no match for my power, for our power. You hold back and use your magic to protect Arthur when you could have others fearing your name and bowing at your feet. Imagine Prince Arthur bowing down to you."

"I don't want that," Merlin spat aloud. "My duty is to serve Arthur not to make him serve me. I will do everything it takes to insure his safety. Even if that means killing you."

"My my. Such a strong word for a pathetic man," Emrys accused.

Merlin stopped in his tracks as his head suddenly felt like someone was stabbing his brain. He grabbed at his hair and shouted as his knees made contact with the dirt.

"You're brain can't handle all these memories. Not since I've used magic to keep them hidden for so long." Emrys's voice pierced through his pain. "The further along you get, the more intense they're going to become and let me tell you ... You won't like some of my memories."

Merlin gritted his teeth so hard he felt as if he might chip them. He wanted to shout back, "I don't like any of your memories!" but talking through the pain was impossible.

Another flashback sprang to mind, but this one played out like a scene. Like a dam had just burst and everything flooded through at once.

Emrys stood before a cave, hatred present in his eyes.Taking confident steps, he marched into the cave and with one simple spell—one Merlin knew quite well—a ball of fire filled the palm of his hand. He stomped through the narrow passage ways until he came to a good size chamber that looked like it had been dug out to become a home.

Looking right, he found a man hunched over a small fire poking at the burning wood with a stick. "Balinor," Emrys bellowed, the word bouncing off the cave walls.

The man, his hair long and grey, jumped to his feet and twirled around. He furrowed his brow, his eyes old and worn. "How did you find me?"

Emrys balled his free hand into a fist. "It isn't hard if you interrogate the right people." He took a few steps forward. "I've been dreaming of this moment for a very long time."

Balinor stepped back. "Do I know you?" He peered at the fire in Emrys's hand. "You're a sorcerer?"

Emrys smirked. "Let's just say, you know part of me."

"Your face." Balinor squinted. "It looks vaguely familiar." Emrys straightened his back standing taller, and after a few more seconds, Balinor's jaw dropped. "It can't be. Merlin?" He chuckled. "You were just a lad when I left."

"Wrong!" Emrys said sharply. "Guess again."

The small grin that was plastered on Balinor's face dropped instantly and he shook his head. "No." He sighed what clearly sounded like defeat. "So, what do they call you then?"

"Emrys," Emrys replied with a smile.

"And what are you doing here, Emrys?" Balinor pressed. "I take it Merlin doesn't know you're here."

Emrys shrugged as he lowered his hand extinguishing the flame. "Merlin doesn't even know I exist." Balinor's eyes widened. "I'm here to do the same thing to Merlin that you did to me." He paused and his sly grin dipped with anger. "Leave him fatherless like you left me."

In a quick flash, Balinor threw out his hands, but Emrys was faster. He, too, threw out a hand but a dagger that had been hanging on his belt followed suit. Before Balinor could react, the dagger pierced him in the stomach. He stared at Emrys blankly before stumbling back colliding with the rocky wall. A second later, he slid down to the ground and laid there lifeless.

Merlin clawed at the grass, dirt burying itself underneath his fingernails, and he wept. "No," he whispered, shaking his head. Unable to contain the rage that boiled in his blood, he dug his nails deeper into the ground and shouted. His whole body shook and he felt a blast of magic escape his body. Several trees around him suddenly exploded into millions of pieces flying through the air. He quickly curled up into a ball on the ground to protect himself from the shards of wood.

When everything around him settled, Merlin slowly stood. "You!" he spat. "You killed my father."

"And he killed mine!" Emrys shouted back. "I think it's fair to say we're now even."

"Fohlian killed hundreds of people and abused the dragons. Fohlian deserved to die."

"My father was one of the greatest dragonlords alive and Balinor found a way to wipe him out. If you ask me, it was Balinor who got what he deserved."

Turning around facing the direction towards the Citadel, Merlin pressed on. "You'll never get away with any of this. Not taking over Camelot and certainly not controlling Kilgharrah."

"Oh, please," Emrys spat. "I've known about being a dragonlord for years, Merlin! I've had a lot more time to study and learn the tongue. What makes you think you could figure it out in one day?"

Merlin smirked. "I've always been a fast learner, and the fact that Kilgharrah is still in chains makes me believe that you haven't figured out the dragons tongue yet." There was nothing but silence. "Enjoy the time you have left, Emrys, because soon you'll join our fathers."

The next several hours were excruciating, and day was finally starting to break. The headaches were getting worse. More and more, Merlin was remembering what Emrys had done and who he had all killed. It just enraged him further.

Relief washed over him as he stepped out into the field that separated him and the Citadel walls. Stumbling through the tall grass, Merlin hurried excitedly. Once inside the walls, he felt awkward lunging over from the hammer to his head as the villagers looked on with confusion. A few mothers even pulled their children in closer out of fear to avoid him.

It was at this moment that he realized he wasn't going to make it. A few more steps and this would all be over, but he just couldn't. He shuffled to the left and stumbled his way to a familiar home he visited often. He nearly collided with the door and pounded his fist against the wood loudly. He just had to hope she was home. Seconds later, the door swung open.

"Merlin?" Merlin looked up to find Gwen worriedly staring at him. "You've been missing for days! We were all worried sick about you after what happened." She eyed him up and down. "Merlin, are you alright?"

"Gwen," he huffed out. He hunched over at the abrupt eruption of pain and gritted his teeth. He staggered but caught himself against the doorpost. "I need your help," he said in deep desperation. "I can't stay awake any more." His eyelids had already become super heavy.

"What do you want me to do?" Gwen asked, widening the door for him to come through, only he didn't.

Merlin placed a hand on his chest. "I need help to escape this ... monster inside of me."

Gwen furrowed her brow. "I'm sorry I don't understand."

"Get Gaius," was all he could say through his panting. "I can't make it there or I'd get him myself."

Gwen nodded without further questioning. She reached for her shaw on the coat rack, but Merlin gripped her tricep halting her from leaving. "One more thing," he said. She looked at him intently. "I need you to tie me up."

Gwen snorted, but when Merlin didn't crack a smile, her expression turned quizzical. "Wait, you're serious."

"Gwen, please!" He hated being so harsh, but time was running out. His eyelids became too heavy and his legs weakened. "You have to hurry before ..." He trailed off as his knees buckled. "Before he hurts anyone else." The last thing he remembered was hitting the ground.

"Merlin?"

He heard his voice ringing in the distance and he slowly tried picking up his head. His eyelids fluttered as his vision zeroed in on the man before him. After a few seconds, his long grey hair and blue robe became more clear, and Merlin smiled. "Gaius."

His head ached and he went to move but found his arms wouldn't budge. Blinking away the fog, he looked down to find his hands tied behind the chair he sat on and his ankles bound to the legs. Furrowing his brow, he looked up as Gwen stepped into view.

"You asked me to tie you up," she said, pointing to the ropes.

Recalling their conversation, his face relaxed. "Oh, right." He was relieved to find Emrys still tucked away inside although he knew his moment of unconsciousness gave him the opportunity to weaken the barrier quicker. Time was ticking away and he could feel that he had hours left before his chance at getting rid of Emrys was gone for good.

"Merlin, what's going on?" Gaius asked, stepping around the chair to untie Merlin's wrists. "Where have you been?"

"I don't have time to explain, Gaius. I need your help." He bent over to untie his ankles and the stabbing in his brain returned along with a flash of Emrys's memories.

"I was right all along," Merlin said, frantically, leaping from the chair. He twirled around to face Gaius. "It was me doing those killings." He paused. "Well, kind of me."

"Killings?" Gwen's voice heightened with her astonishment.

Merlin glanced between the two and his expression sadden. Like he was hearing his next words for the first time. "I have a darker half," he said slowly.

Gaius crossed his arms. "Merlin. Don't we all?"

Merlin shook his head. "No, you don't get it." He pointed at his chest. "He's living inside me! A part of me. A piece of me. This other person living a whole separate life." The two stared dumbfounded at him.

Gwen smirked. "No, that's ... that's impossible." She looked past Merlin to meet Gaius's gaze. "Right?" Gaius didn't answer.

Merlin ignored Gwen, knowing that Gaius had no reason to not believe him and continued, "Emrys found Morgana—"

"Emrys?" Gaius interrupted. "I've heard that name before."

"He and Morgana plan to attack Camelot soon," Merlin went on.

"How soon?" Gaius asked, gripping the back of the chair.

"Uh ..." Merlin shook his head and thought hard back on Emrys's memories over the past few days. "Anywhere from a few hours to a couple days," he answered, exhausted. He couldn't keep a frown from escaping. "I'm sorry, Gaius. I really don't know."

"It's fine, Merlin, but we need to inform the King." As Gaius took a step to the side to maneuver around the chair, the pain in Merlin's head intensified and his vision suddenly went black for a split second causing him to tumble forward landing on all fours as he shouted through his gritted teeth.

"Merlin!"

His vision cleared and he felt a shaky hand around one tricep and a pair of rough hands around the other. Gaius and Gwen helped him to his feet.

Merlin spun and gripped Gaius by his forearms. "I need a spell that will put me into my mind," he desperately pleaded. "Please, Gaius."

"Into your mind?" Gaius asked, returning the tight hold.

Merlin panted as the pounding made his head spin and vision blur. "It's the only place I can see him. The only place I can fight Emrys for control."

Gaius looked down as he thought. "I swear I've heard that name before." Merlin, through squinted eyes, gazed at him confused. Gaius's head popped up as his jaw dropped. "It was just rumors, but the Druids talked about a man named Emrys who was supposedly destined to kill Arthur."

Another memory unexpectedly returned and the agony brought Merlin back to his knees. Thankfully, Gaius held onto him by the elbow keeping him from falling to all fours. They were starting to get closer together. Hunched over, he looked up and squeezed out, "And now you know why I must defeat him."

Gaius shook his head. "But I never imagined that Emrys would also be you, Merlin. If the rumors are true, Emrys is very powerful. Very dangerous."

"We share a body, Gaius." Merlin halted and gritted his teeth with a yelp before continuing. "Whatever magic he has, I have."

"But you're not used to practicing all your magic," Gaius objected. "Especially not dark magic."

"What's this about magic?" Gwen interjected, her tone signifying that she was scared about the whole conversation. "Merlin has magic?"

The pain in Merlin's head was getting worse and he was tired of trying to make Gaius understand. "Gaius, please!" He pushed his father-figure away and fell to the floor with a shout, grabbing his head. "Just make the draft!"

"What do I need?" Gaius asked, taking off towards the door. "Gwen come help me."

Through gritted teeth, Merlin spat, "I don't know. Balinor said you'd know what book to find the ingredients in."

"Balinor?" Gaius asked, shocked.

"Not now, Gaius!" Merlin pounded a fist into the wooden floor.

"I think I know of a few books the spell could be in. Balinor didn't say anything specific that we need, did he?"

Merlin rested his head on the floorboards panting as the headache died down. "No. If Emrys sees what we need he'll try to sabotage the draft." He sat back on his heels and let out an exhausted sigh. "Please hurry. I can't hold him back for long. I can already feel the walls coming down, and I'm too exhausted to hold him back."

"We'll be back in no time," he said, placing a hand on the door handle. "Gwen, tie him back up."

Struggling to stand, Merlin placed a hand on the nearby table and pushed himself the rest of the way to his feet. Turning towards the door, he said, "No. I need to go warn Arthur. Morgana could be on us at any moment."

"Merlin, you're in no condition to be doing so. Especially if Emrys decides to make an appearances while talking to Arthur."

Shaking the dizziness away, he dashed for the door. "What choice do we have, Gaius? Camelot can't be unprepared. Arthur must know."

"Then let me tell him." Gwen stepped forward.

Merlin shook his head. "No, Gaius will need all the help he can get if we are to make the draft before Emrys takes control." Ignoring Gaius's protest, Merlin pulled open the door and dashed down the cobblestone to the Citadel.