It was past midday by the time Merlin left Camelot. He had taken some painkillers for his constant headache and soreness, but he still felt like he was walking through molasses. The bustling of the city around him could hardly be heard over the ringing in his ears. Merlin considered turning back several times, but now that he was out of the castle, the link was growing stronger. It felt like Merlin was being physically pulled out of Camelot and closer to her.

As Merlin reached the gates to the citadel, he felt an awful churning in his stomach. His magic. It was warning him to turn back. With great effort, the warlock stopped walking. However, when he tried to turn back, pain spiked in his forehead and he choked back a yelp.

There was no question about it now. Merlin had made his decision and there would be no turning back.

Taking a deep breath, Merlin continued forward until he was out of the city walls. He nodded to the guards positioned there and they nodded back, familiar with Merlin's habitual herb-picking. The sun felt nice on his face, and Merlin realized that he hadn't spent much time outside since this whole thing started. He had forgotten how much he loved the open air and the freedom and solitude had granted him from time-to-time.

But soon, Merlin's own feet had dragged him from the sunlight and into the thick forest ahead. The woods were unusually quiet, devoid of the usual sound of birds and other animals rustling in the undergrowth. Merlin found it unsettling. In the eerie silence, it didn't take long for Merlin to pick up on the small sounds coming from behind him. Someone had been trailing him. Merlin paused, turning his head back.

"I know you're there. Come out and face me."

The trees swayed innocently around him. The forest remained quiet.

"Face me," Merlin demanded, his voice dripping with rage.

Something emerged then from the bushes. Merlin held a hand out, prepared to cast a spell, but he recognized the brown mop of hair and the chainmail coming his way. Merlin sighed exasperatedly, lowering his hand.

"Gwaine! Why are you following me?" Merlin said through clenched teeth.

Gwaine still had his hands up in mock surrender as he closed the distance between them.

"I was going to come talk to you in the lower town, but then you were acting all flighty and didn't even notice me standing there." Gwaine's airy expression melted into a frown. "What are you doing out here?"

Merlin rolled his eyes. "Collecting some herbs, like I always do."

Gwaine hummed. "Want some company?"

Merlin did, and he wanted desperately to say it. He was tired of fighting alone and lying to his closest companions, but in the end, he did it for their safety.

"No, Gwaine. I'll be fine."

Gwaine frown did not soften. "Merlin, something's been going on with you lately. We've all noticed, and everyone's worried. You don't have to tell me what's going on, but I'm coming with you."

"Gwaine, I'm—"

"If you say fine, I'll break your nose."

Merlin couldn't help but smirk, and Gwaine returned it with a lopsided grin. Merlin really was grateful for his concern, even if it made things more difficult for him. Merlin continued on through the forest, now with Gwaine at his heels. There was no way that Merlin could turn back now with that horrible pain in his head, so Merlin would just have to figure out a way to fight this thing without revealing himself to Gwaine.

This day just got better and better.

…

Council meetings always dragged on and on, but today had been especially slow. All the king could seem to think about was how Merlin was getting worse and how scared he was. Arthur often called Merlin a coward, but in truth, he had never seen Merlin afraid.

Arthur trudged straight to the physician's chamber after the council meeting had concluded. He groaned internally at the thought of another night of research, but those thoughts quickly fled his mind when he opened the door.

The room was chaos. Books were strewn about, as if an animal had torn through them. When Arthur spotted Gaius, the old man's eyes were frantic and filled with worry.

"Gaius, what—"

"Merlin's gone."

"What?" Arthur spun back around, sprinting for the door. The idiot. He'd gone and done it now. He went after it. By himself. Arthur could scream.

"Sire, wait!"

"I have to find him!"

"I know, but first, I know what the creature is."

Arthur spun on his heels, once again facing Gaius. The old man looked wild as he held open a massive book for Arthur to look at.

"A succubus?" Arthur asked, reading from the print.

"Yes, but a rare subspecies. That's why it took me so long to figure it out. The succubus is a female demon that typically seduces its victim in his sleep. However, this particular one feeds off of men that have strong psychic energy before luring them in to be drained entirely."

Arthur swallowed. "Drained how?"

Gaius grimaced. "I'm not sure. It's not clear, but it can't be good. This creature can drain people instantly, or hold them captive for weeks by feeding off them slowly, depending on its preference."

"And then?" Arthur's heart was pounding.

"Eventually, they die."

Arthur's fist clenched. This demon had already gone too far. There was no way Arthur would let it get Merlin. It would never see another day.

"How do I kill it?" Arthur all but growled.

"That's the tricky thing," Gaius said with a sigh. "It has a physical body, but it cannot be killed by any weapon. It must be killed where it manifests its power—in the link between Merlin and its own mind. That link is its biggest weakness. If Merlin can sever it, the creature will perish."

"There has to be another way. Have you seen Merlin lately? He can't fight this thing off by himself!"

"You underestimate him, sire. His body may be suffering, but his mind is strong. He has resisted this creature far longer than most can. You must tell him how to fight it, but it will be up to him to destroy it."

Arthur's stomach churned. He always knew how stubborn and strong Merlin really was, but Arthur hated that he was still powerless to help him. To protect him. It hurt like a festering wound in his gut.

As Arthur steeled himself to make for the stables, he felt a gentle but firm hand on his arm.

"One more thing. This creature can appear as anything it wants to. Do not trust anyone."