A/N: I'm back with more incubus!Sherlock goodness. For the sake of categorizing, I'm calling my version of Myrddin/Merlin an OMC. This is a work in progress. I'll try to get new chapters up weekly but no promises.

Disclaimer: It all belongs to the BBC.

Molly Hooper woke to the feeling of soft lips kissing her neck. She smiled to herself. "Good morning, sexy."

"Good morning, love," Sherlock murmured between kisses.

She was laying on her side, her back to him. He wrapped his arm around her waist, his bare chest pressed against her back and his cock pressed against her bum. Ever since his proposal a month before, Molly had given up on wearing anything to bed since he ended up taking it off her anyway. Sherlock, of course, never wore anything to bed.

"Mmm, I see you're wide awake," she murmured.

"You know me, always an early riser." His hand slid to her left breast, cupping it gently, his thumb stroking her nipple into hardness.

She moaned his name softly, her bum pressing back against his cock. She reached behind her to stroke it when her mobile rang. Both of them groaned.

"Don't answer that," he murmured in her ear.

"I have to see who it is." She picked up the phone. "It's Prof. Llewellyn."

"Your father's old friend?" Sherlock asked. He started kissing her shoulder.

Molly couldn't help smiling. "Yes. Sorry, Sherlock, but I have to take this. Behave." She batted his hands away then pushed the button. "Hello, Professor."

"Molly, hello," the old man said. "I have something on Merlin."

"Oh, yes. Thank you for calling me back. I'll take any info you can give me." She grabbed a small notepad and a pen from the nightstand.

"In Carmarthen, there's an oak on the corner of Oak Lane and Priory Street. Huge, massive thing. It's known as Merlin's Oak, local legend says he planted it. It's the only specific tree that I have been able to connect to him."

Something resembling hope began to swell in Molly's chest as she wrote down what he said. She'd been looking for any clues as to which tree Nimue had trapped Myrddin in and had been asking every Arthurian scholar her father had known, saying she was writing a romance novel about Merlin. "Professor, that may be just what I need to finish my book, thank you!"

The old man chuckled. "You're welcome. Of course, you'll have to hurry if you want to see it – it's scheduled to be cut down next week."

"What? Why?"

"Some 'expert' says it's dying. It looks perfectly healthy to me, but the city council is worried it'll drop a limb and crush someone. Better see it while you still can."

"I will, Professor. Thank you." She said goodbye then hung up. She turned to Sherlock and couldn't help smiling at his disappointed look. "Sorry, love. But Prof. Llewellyn had good news – he found a tree in Wales that may be the one. But the tree's going to be cut down next week so we have to go now." She quickly got up and started to get dressed.

Sherlock groaned in frustration. "If it's not going to be cut down for another week, what's the hurry? Myrddin has waited almost a millennium and a half, he can wait another hour. I didn't even get my good morning kiss." His plush lips formed a pout. "That's it, I'm banning phones from the bedroom."

Four thousand years old and he pouts like a child. Molly chuckled as she put on her bra and panties. "Nope, sorry, some calls are too important to miss." She leaned to kiss him softly. He kissed her back eagerly and when he tried to pull her back into bed, she just laughed and moved away. "If you had been trapped in a tree for fourteen hundred years, wouldn't you want someone to free you as soon as possible?"

Sherlock grumbled something and Molly stopped dressing to stare at him. What is his problem? He sounds like he doesn't want to find Myrddin. It makes no sense. She pulled on her jeans then walked over to him just as he was pulling on his trousers.

"Love? What's wrong?" Molly asked softly, wrapping her arms around his waist.

He sighed quietly as he wrapped his arms around her. "I keep wondering how Myrddin will react when he sees me. I'm sure his mother told him I'm an evil demon who seduced then abandoned her."

"You're changed, Sherlock." She brought her hands up to frame his face, saying softly, "You're a good man. He'll see that."

Sherlock lowered his head to kiss her deeply. "You're the first person to believe in me, Molly," he murmured. "I will always be grateful for that."

She smiled softly. "You'll get the chance to demonstrate your gratitude later, I promise." She helped him into his shirt then pulled on her jumper as he pulled on his suit jacket.

"The fastest way to get there is to go through Hell." He held out his hands, smiling a bit. "Ready?"

Molly took his hands. "As I'll ever be." They had taken Sherlock's little shortcut once before. He had told her to keep her eyes closed but Molly hadn't listened. The brief glimpse she'd had of Hell was enough to give her nightmares for days.

This time, she closed her eyes. There was a blast of heat then she felt heavy rain soaking her and heard a loud clap of thunder. Molly opened her eyes and found herself and Sherlock on a deserted street corner in the middle of a violent thunderstorm.

"We should've checked the weather in Carmarthen before we left," Sherlock shouted above the storm.

"Too late now," Molly shouted back.

He grasped her hand and lead her to the corner's main landmark – an ancient oak tree. Just as they were approaching it, a bolt of lightning struck the tree, setting some of the leaves on fire. Sherlock and Molly jumped back, Molly covering her ears. After the rain had put the fire out, Sherlock approached the tree again, gesturing for Molly to stay where she was. He examined the trunk, which was large enough to hold several people, then he turned to Molly and she could see his eyes were huge.

"He's here, we have to get him out!" Sherlock shouted.

It suddenly occurred to Molly that she had spent so much time looking for Myrddin, but spent no time figuring out what they would do if they found him. "How do we free him?" she shouted back.

"We have to hope my blood and powers are enough!"

The fingernail of Sherlock's left index finger extended to a claw, which he used to slash his right palm. Molly winced as dark red blood oozed from the wound. Sherlock slammed his bleeding palm against the trunk with all his might, shouting something that to Molly sounded like Latin, but it was hard to make out individual words in the storm.

White light shot out from under his hand then where the front of the trunk had been, there was now a man wearing black robes with long, scraggly brown hair and an equally long and scraggly beard. His eyes were closed but he opened them after a moment. Even from where Molly stood, she could see he had Sherlock's eyes. He looked out at the rain-soaked street and buildings beyond and suddenly started to fall forwards in a dead faint. Sherlock caught him before he hit the ground. Holding Myrddin upright with one arm, he reached for Molly with his free hand. As soon as her hand touched his, there was another blast of heat then they were in the sitting room.

"We have to get him out of those wet robes," Molly said.

"I'll do that, you should change," Sherlock said.

She peeled off her sodden jumper on the way to the bedroom. By the time she came back out in her pajamas, Sherlock had laid Myrddin on the sofa and had removed his robes, leaving him in a pair of white breeches. His skin was pale, like Sherlock's own, and Molly could see scars from defensive wounds on his arms.

"Sherlock, let me take care of him," she said gently. "You need to change."

Sherlock, who had been staring at Myrddin like he didn't know quite what to make of him, looked down at himself. He snapped his fingers and was dressed in a dry black suit and his aubergine dress shirt. Even his curls were dry.

Molly rolled her eyes fondly. Showoff. "Do you have something he can wear?"

Sherlock snapped his fingers again and Myrddin was dressed in Sherlock's black pajamas. Molly looked him over.

"He looks like how I'd expect Merlin to look, but younger." She looked up at Sherlock. "He has your eyes."

He nodded. "And his mother's hair." He looked him over. "If he doesn't wake up soon, I'll take him to the guestroom." He looked at Molly, saying gently, "I have no idea what state his mind's in, love. The confinement could have taken his sanity. At the very least, he'll think this is still the Seventh Century."

"I assure you, Father, my mind is perfectly sound and I am well aware that this is the Twenty-first Century," came a deep, tired voice from the sofa.

Sherlock and Molly turned in unison to the sofa. He sounds just like Sherlock, Molly thought.

"You know who I am?" Sherlock asked, surprised.

Myrddin sat up slowly. "Of course. We've never met," the accusatory tone in his voice was crystal clear, "but I would know you anywhere."

"I spent a century of torment in Hell because I wasn't there when you were born," Sherlock said quietly. "As soon as I was released, I tried to find you. You were already in the tree by that time but I had no idea."

"You gave up!" His hands were clenched into fists and Molly would swear she saw tiny bolts of lightning moving along them.

"You don't know that," she said defensively. "Sherlock was devastated that he never got to know you."

Myrddin looked at her and Molly suppressed a shudder at the ice in his eyes. "I'm clairvoyant, Dr. Hooper. My mind can see everything happening in the world beyond what my eyes can see. I saw my father give up. For fourteen centuries, I waited for someone to find me. That it was my father's ordinary fiancée who found the right tree is ironic." He stood up and started to sway, but held up a staying hand when Sherlock tried to help him. Myrddin turned back to Molly. "I seriously doubt my relationship with my father will be repaired in time for your wedding."

Molly stared at him in surprise then shook her head. "Is there anything you don't know?"

"Very little. The future is hazy, but the past and present are crystal clear." He looked down at his beard then a hand went up to his hair. "I need to clean up."

"I'll get Tom's razor and the shears," Molly said. She left the kitchen and walked to the bedroom. A black tail was sticking out from under the bed. Molly smiled to herself. "So, this is where you've been hiding." Unlike her previous cat Toby, Devil didn't like strangers. She found Tom's straight razor in the cabinet under the bathroom sink and the shears her beautician mother had given her then walked back to the kitchen. Not for the first time, she silently thanked her late mother for teaching her how to cut hair when she was younger.

Sherlock and Myrddin were silently glaring at each other. Molly couldn't help rolling her eyes. Men.

"Molly, Myrddin is insisting on leaving," Sherlock said.

"I have no reason to stay," Myrddin said.

So much for gratitude. "Don't be silly, Myrddin," Molly said firmly. "You're family and we have a perfectly nice guestroom." Myrddin started to protest but she cut him off. "This discussion is closed. Now c'mon, let's get you cleaned up. The guest bathroom is this way." She turned and headed down the hall. Behind her, she heard the two men talking.

"Is she always this … formidable?" Myrddin asked, sounding a bit dazed.

She heard Sherlock chuckle. "Yes, actually."

Molly smiled to herself.

It took a good deal of effort on her part and "helpful" comments on Sherlock's part, but eventually Myrddin was clean-shaven and his thick, straight brown hair had a modern cut and style. Molly suggested leaving the fringe in front but Myrddin insisted on slicking it back. She thought it made him look even more intimidating.

Molly looked back and forth at the two of them. With the short hair and no beard, Myrddin's prominent cheekbones, inherited from Sherlock, were evident.

"You two look like brothers instead of father and son," she said. "That's probably the story we should tell people."

Sherlock nodded. "We'll say he's staying with us for a while."

"I'll find my own place as soon as possible," Myrddin said coldly. "Far be it from me to intrude on your privacy."

"You need clothes," Molly said, ignoring his comment. "I'm sure your father can lend you some until we can take you shopping. Right, Sherlock?" She smiled at her fiancé.

Sherlock idly wondered if he had gone back to Hell without realizing it. He was slumped in a chair by the men's fitting rooms, bored out of his mind. His fiancée was standing beside him, waiting for Myrddin to come out.

"You could show a little enthusiasm, Sherlock," Molly admonished gently.

Sherlock rolled his eyes. "You know I hate shopping," he muttered. "He could show a little gratitude. We did save his life, after all."

"He spent fourteen hundred years by himself, maybe he forgot how to act around people."

"Hey, you two," came a familiar voice.

Both of them turned to see John and Mary approach. John was pushing a stroller and Mary was holding Rosie on her hip.

Molly smiled happily. "Hello, Watsons."

"Fancy meeting you here," John said, grinning. "Mary wanted to get me some new jumpers."

"Something not so eye-searing," Mary said, smirking. "Shopping for a new look, Sherlock?"

"Hardly," Sherlock muttered as he stood up. The Watsons and Greg had become Sherlock's friends too, though none of them were aware of his true nature. He couldn't help smiling a bit at Rosie.

"They're here for me," Myrddin said as he came over, two pairs of jeans in his hands. He smirked at John and Mary's double-take then held out his hand. "Merlin Holmes, Sherlock's brother." He used the surname Sherlock had given himself and Sherlock nodded in approval.

John shook his hand. "John Watson. This is my wife Mary and our daughter Rosie."

Mary shook Myrddin's hand. "I didn't know Sherlock had another brother, I've only heard him mention Mycroft."

"I've been out of the country for years," Myrddin said, "and we didn't communicate much. The airline lost my luggage, Sherlock and Molly are helping me find replacements."

"That's horrible," Mary said sympathetically. "Thank God for family."

"Indeed," Myrddin muttered.

Sarcasm, my family's native language, Sherlock thought, sighing. Just behave yourself around our friends, that's all I ask.

When the shopping was done, Mary suggested they go out to lunch together. After they were seated at a table, she smiled at Myrddin.

"So, Merlin, tell us about yourself. Are you a butler like Sherlock?"

"No, I'm a stock broker. I always have one eye on the future."

Molly choked a bit on her drink but covered it with a cough. Sherlock smiled slightly.

"Are you seeing anyone?" John asked.

"No. My last relationship ended badly, I've been on my own since then."

That's one way of putting it, Sherlock thought.

"Perfect!" Mary said, beaming. "I have a friend who's single."

"Mary, Merlin just got to town," Molly said. "I'm sure he wants to find his feet before he starts dating again."

"If I start dating again," Myrddin said. "I think I should concentrate on other things right now."

After lunch, the Watsons left to take Rosie to the park while Molly, Sherlock, and Myrddin went back to the flat. Myrddin took his new clothes to the guestroom and Sherlock decided to hunt down a recipe for dinner. He was deep in a food blog when Molly came over to him.

"What do you think Myrddin's plans are?" she asked. "I mean, King Arthur is long dead."

"Not dead, Dr. Hooper, just sleeping," Myrddin said as he entered the kitchen. He was wearing some of his new clothes – tight blue jeans, a red pullover jumper over a white t-shirt, and white trainers.

I can't believe my son prefers casual clothes over suits, Sherlock thought, shaking his head.

"Until England has need of him again?" Molly guessed. "England has needed Arthur many times since the Sixth Century but he never came."

"He will come at the time of England's greatest need. Be grateful you haven't seen it yet."

"Have a care in how you speak to your future stepmother," Sherlock said sternly.

Molly said quickly, "Sherlock, it's fine."

"No, it's not. This is our home, I insist that he respect us while he's here."

"There's an easy way to fix that," Myrddin said. "I'll leave."

"No one's leaving," Molly said firmly. "Myrddin, if you can't at least be civil, then you can be quiet."

Myrddin looked at each of them and muttered something under his breath. "Very well. If you'll excuse me." He left the room.

Sherlock turned to Molly, raising an eyebrow. "Maybe we should have transplanted the tree instead."

Molly just laughed.

"I have a job for you, my dear," Mycroft, Anthea's boss for over a century, said. He sat behind his desk, his hands folded in front of him.

"Yes, sir?" Anthea asked.

"My younger brother has finally seen the light but cannot break his contract with Hell. Considering how helpful you are to me, I thought you could assist him."

Externally, Anthea didn't so much as blink at his request, but internally she was screaming. After a moment to collect herself, she asked carefully, "Sir, wouldn't I be of more use to you here?"

"Sherlock needs all the help he can get. Since I have far too much on my plate, you will take my place. This is not a request, Anthea."

"How, exactly, do you think I can help him?"

"You're a resourceful woman, I'm sure you'll think of something. At the very least, you'll be a valuable asset should violence erupt." He smirked. "You'll remember that I've seen you in battle."

Yes, from the sidelines. She was grateful to Mycroft for recruiting her from Heaven's army, but now she wondered how long she'd be in his debt. "When do I leave, sir?"

"Momentarily. Of course, you'll have to use a human form, we can't have you blinding Sherlock's mortal fiancée. You cannot take anything with you – you will be completely dependent on others' generosity, like every other angel who visits Earth. And I will remind you not to give in to temptation – angels are above physical desires, after all."

Anthea mentally rolled her eyes. I've heard all of this since I was created. "Yes, sir."

Mycroft nodded. "Off you go. And do give my brother my best."

"Yes, sir." Anthea left his office, mentally treading on Mycroft's smug face with each step she took. Two days of dealing with paperwork himself and he'll beg me to come back. In the blink of an eye, she appeared in human form outside of Sherlock and Molly's flat. She shrugged her shoulders, suddenly missing the weight of her wings between her shoulder blades, then looked at her hands. For the first time in her existence, she wasn't glowing. This is going to take some getting used to.

She took a deep breath then knocked on the door. She heard voices coming from within the flat then the door was opened by the very incubus she was sent to save.

Said incubus looked her over, raising an eyebrow. "What do you want, angel?" It wasn't an endearment. "Did my brother send you?"

Anthea nodded. Of course he didn't tell Sherlock I was coming. "Mycroft thought you needed an extra pair of hands. I'm Anthea." She held out her hand.

He shook it. "Sherlock, but you already knew that." He stepped aside.

She walked into the foyer and heard her stomach rumble loudly as she caught the scent of food coming from the kitchen. Sherlock chuckled as she blushed.

"First time in human form?" he asked, amused.

She nodded. "I was a soldier until your brother recruited me a century ago. This is my first mission on Earth."

"A word of advice – enjoy yourself while you can."

Anthea raised an eyebrow. "That's exactly what I can't do."

"Who knows when you'll be like this again? Don't go back to Heaven with regrets."

"Angels exist to be obedient, or has your time as a demon erased that from your memory?"

He smiled a bit. "Every angel has a little rebellion in them. Better to blow off steam here and return than spurn Heaven entirely out of built-up frustration."

"Is that what happened to you?" she asked, curious.

"That would be telling," Sherlock said, smirking. "C'mon."

He led the way down the hall and into the kitchen, were a human woman Anthea recognized as Sherlock's fiancée was skinning potatoes. She looked up when they came in.

"Molly, this is Anthea. Mycroft sent her to help us break my contract. Anthea, this is Molly Hooper, my fiancée."

Molly held out her hand, smiling. "Hello, Anthea. We're happy to have you on our side."

"Thank you, Dr. Hooper." She shook her hand.

"Please, call me Molly. Are you joining us for dinner?"

"Actually, she'll be staying here," Sherlock said.

Molly raised an eyebrow at him. "Um, love, we only have one guestroom and that is currently occupied."

"I'm hoping Myrddin will be a gentleman and cede it to her."

"I don't want to cause any trouble," Anthea said.

"There'll only be trouble if Myrddin's not cooperative," Sherlock said.

Myrddin lay on the bed in the guestroom, still fully-clothed. He stared up at the ceiling, wondering exactly what he was supposed to do next. I need my own place, this flat is already stifling. Unfortunately, I have no money to my name. Father has plenty of money, those bank accounts of his go back a couple of centuries, and he would give me some if I asked. But the last thing I want is to be indebted to him.

The smell of food and the sound of more than just Sherlock and Molly's voices caught his attention. Curious, he got up and walked to the kitchen. His father and future stepmother were talking to a woman with her back to him. Her brown hair was in a French twist and she wore all-white – blouse, pencil skirt, and heels. It was her scent, though, that really got his attention. Incense and lilies? I know that scent.

"What the hell is an angel doing here?" he demanded.

A/N: There really was a Merlin's Oak in Carmarthen, Wales, but according to Wikipedia, the original tree died in 1856.