Title: The Houses of Pendragon, Emrys and Potter

Summary: AU OotP, set after M-S5. Merlin had always watched as the wizarding world fought for justice. He watched Harry Potter grow up as a young warlock struggling against Voldemort. At the Department of Mysteries on a Thursday evening when a deadly battle was playing out concerning Harry's destiny, Merlin decided it was time to step in. He will join the fight. This time. DISCLAIMER NOW!

Written by: Alexia Blackbriar (hoping to co-write with Holmes1216)

PLEASE REVIEW.

MULTI-CHAPTER STORY.

This will include Harry, Hermione, Ron, Ginny, Luna, Neville, Hedwig all of the members of the Order (including Sirius), the Professors, the characters from Book 5 and Book 6, Aithusa, Merlin of course and there will be mentions of Merlin S1,2,3,4,5.

DISCLAIMER: Some of this work belongs to the brilliant JK Rowling. I cannot take credit for her stuff! All the characters either belong to HER or the BBC.

AU Please review and I have tried my best. PLEASE CAN YOUR REVIEWS BE POSITIVE!

"Who's Professor Slughorn?" asked Neville, looking perplexedly at his own invitation.

"New teacher," Harry told him. "Well, I suppose we'll have to go, won't we?"

"But what does he want me for?" asked Neville nervously, as though he were expecting detention.

"No idea," said Harry, which was not entirely true, though he had no proof yet that his hunch was correct. "Merlin?"

Merlin was quietly reading his own letter. He looked up at them, looking worried, before levitating the letter and causing it to burst into flames with a flash of his eyes. Nobody flinched, but they stared curiously.

"I knew this would happen," moaned Merlin. "Harry, I can't go. Slughorn knows who I am, that's the only reason he wants me."

"Go on, mate, it won't be so bad," said Ron, though he looked sympathetic.

"No, I can't go, I swore to myself I'd stay under the radar." Merlin was shaking his head frantically. "Harry, you'll just have to tell him that I had to leave to help the Order or something."

"Alright, then," Harry said, though he was slightly disappointed that he would be going to this lunch with only one of his friends. "Listen, Neville," he added, seized by a sudden brainwave, "Let's go under the Invisibility Cloak, then we might get a good look at Malfoy on the way, see what he's up to."

Harry and Neville departed for the lunch, and Merlin could only hope that his plan would work. Luna went back to reading The Quibbler without another word, still wearing the massive Spectrespecs while Hermione and Ron turned to bombard Merlin with questions. Aithusa clambered down from Merlin's lap to the now empty beside him and curled up on the cushion, tucking her white snout underneath her tail and settling down for a quick nap, while Kilgharrah the eagle-owl hopped from Merlin's shoulder to the luggage rack above, fluffing out his black feathers and placing his head under his wing to sleep.

"How many Dementors?" Ron asked him eagerly.

Merlin grimaced. "Three, four? I'm not sure. All I know is that I made them explode…"

"You exploded four Dementors?" Hermione asked, looking impressed. "Well, I guess you don't need to use a Patronus, with all your Old Magic."

"I can use a Patronus," Merlin told them, shrugging, "It just isn't as powerful."

"What does it take form as?" Ron asked him, standing up and looking out the window to search for the lunch trolley.

"A dragon, naturally," Merlin laughed. "That's what my Animagus form is as well."

"You're an Animagus?" Ron yelped. "Whoa, you have got to show us!

"You can transform into a dragon, that's handy," Luna said vaguely, still reading her Quibbler.

"It's not just handy, it's down-right awesome!" Ron crowed. "Oh god, mate, you have got to show me one day."

Merlin nodded, shrugging. "Sure, why not?"

Hermione gazed at Merlin for a few seconds before asking curiously, "Do you have a wand? Because during school, you can't just use your Old Magic, you have to act normal, like a normal student. You'll have to use a wand."

Merlin nodded, smiling. He reached down towards Excalibur's sheath and the pair were surprised to see not only was it a sword sheath, but a wand sheath as well. Merlin gently pulled out a long, thin wand that was crafted beautifully. Two different types of wood, one a dark shiny cherry and the other a black ebony, were woven around each other in a spiral; the end was carved so that it curled around Merlin's hand and was shaped like an Old Dragon, with two tiny topaz stone eyes.

"I made it myself," Merlin explained, as Hermione, Ron and Luna leaned it, entranced and awed by the design. "Its core is three dragon scales; one from Kilgharrah, one from Aithusa and one from me, as an Animagus. It's carved out of two woods; the wood from the trees on the Isle of the Blessed and the wood from the trees on the Isle of Avalon, in the middle of the Lake. This wand is over four hundred years old and has been blessed by the Lady of the Lake and…" Merlin's eyes watered slightly, "King Arthur and Queen Guinevere of Camelot."

"It must be extremely powerful," Hermione breathed in awe.

Merlin suddenly laughed, as though Hermione's statement amused him greatly; "It's useless." He handed it to Ron. "Here, go on, try it."

Ron took the wand gingerly in his hand, treating it as though it was made of gold. Carefully, he gripped it in his hand and pointed it; "Lumos!" Nothing happened. Ron frowned; "Incendio! Lumos! Protego! Diffindo!" Nothing.

Still frowning confusedly, Ron passed the wand over to Hermione, who flicked it several times, casting a few charms; there was no change, and the wand did not do anything. "It has no magic at all!" Hermione cried out, shocked, as she handed it back to Merlin, who was grinning.

"Nope, none at all," Merlin said, smiling widely. "It channels Old Magic. Only I can use this wand. Because it has a dragon scale core, and I'm a Dragonlord and the scales came from my dragons and essentially me, it only responds to my commands. If I had any normal wand, made out of unicorn hair or phoenix feather, the wand would simply explode because of my level of power. But this wand is joined to me, so works only for me, and is attached to my magic."

"That's incredible," Hermione admitted.

"Thanks," Merlin said gratefully.

The lunch trolley arrived and Merlin paid for all of them, buying pumpkin pasties and also some sweets so that they could share them later on, when Harry got back. All four of them changed into their robes; Luna proudly wore her Ravenclaw blue tie while Hermione and Ron sported red and gold to signify they were in Gryffindor. Merlin changed into his black school robes and swung his Shield Cloak back around him as he attached Excalibur and his wand's sheath to his school belt and his padded harness over his robes. He felt odd; everybody else in the school would be wearing a tie except him, and they would also be wearing black school cloaks while he proudly wore the Pendragon red cape from Camelot.

About an hour later, Neville arrived back from Slughorn's lunch party with Ginny in tow stating that Slughorn had been extremely disappointed that Merlin had not attended.

"Where's Harry?" Merlin asked anxiously. He had an idea – a warning signal calling to him within him – that Harry was once again doing something incredibly stupid.

"He ran off under the Invisibility Cloak," Ginny told him, frowning. "I don't know why…"

Merlin's heart stopped. Very slowly, he turned towards Neville and asked him, "By any chance, were you near the Slytherin carriage?"

Neville squinted, trying to remember. "Yes, I think so. He was following Zabini Blaise, you know, that git from Slytherin –"

Merlin didn't need to hear anymore. He had already leapt out of his seat and was desperately trying to claw the door open. Harry had gone to spy on Malfoy, he knew that much. But Merlin's destiny was attached to Harry's and he could tell that something was about to go wrong.

"Merlin, sit down, the train's stopping!" Hermione cried out, trying to tug him back into his seat.

Merlin wrenched his arm out of her grip as Aithusa and Kilgharrah leapt onto his shoulders. The train was indeed slowing and students were standing in their compartments, heaving their trunks down from the luggage racks as they prepared to make an exit. Merlin sprinted through the corridors while they were still clear and his heart filled with dread as the train lurched to a halt. He hurried out onto the Hogsmeade platform. He could see Hermione, Ron, Luna, Ginny and Neville clambering out of their own carriage, looking around for him anxiously, but Merlin didn't pay any attention to them. Aithusa jumped from his shoulder, spreading her wings to search the train from above.

Something had happened to Harry, and Merlin knew he had to find him. Slowly, the platform emptied and several of the remaining students stared as Merlin sprinted back and forth down the platform, searching in carriages.

"Merlin!"

"Tonks!" Merlin cried out, turning around in relief.

"What are you doing here?" Tonks asked him, confused, walking towards him, clutching her wand. "Aren't you meant to be heading up to the castle?"

"Harry's gone missing," Merlin told her worriedly. "I think he went to spy on some Slytherins but got caught. I can't find him. I think he might be hurt."

Tonks looked concerned and her eyes wandered across the train. Suddenly, she pointed. "Look, there. That's the Slytherin carriage. All the curtains have been drawn, but the lights are on."

"I saw Malfoy come out of their only five minutes ago," Merlin told her, his voice filled with dread. "He looked quite satisfied with something…"

"Quick, go find Harry and get out of there. The train's going to leave for London in a few minutes," said Tonks, looking around. "I'll wait for you here on the platform."

Merlin rushed towards the carriage and yanked the door open; edging inside, at first, the carriage seemed to be empty, but then Merlin heard soft, laboured breathing. Holding his hand out, Merlin's eyes flashed gold. The Invisibility Cloak flew into his hand and Merlin was not surprised to see Harry lying underneath it, his fingers broken and blood trickling down his face from his nose. Rolling his eyes, Merlin uttered the counter- for the curse and Harry gasped, forcing himself upwards so he was on his knees.

"Seriously, Harry, can you ever keep out of trouble?" Merlin said, rolling his eyes, helping Harry to his feet.

Harry wiped the blood off his bruised face with the back of his hand, looking guiltily up at Merlin, who had the Invisibility Cloak stuffed under his arm.

"We'd better get out of here, quickly," Merlin said, as the train windows became obscured with steam and the train began to move out of the station. "Come on, we'll have to jump."

Harry hurried after him into the corridor. Merlin pulled open the train door and leapt gracefully onto the platform, which seemed to be sliding underneath them as the train gathered momentum. Harry followed him, staggered a little on landing, then straightened up in time to see the gleaming scarlet steam engine pick up speed, round the corner and disappear from view.

The cold night air was soothing on Harry's throbbing nose. Tonks ran up to them both, Kilgharrah and Aithusa on her shoulders. The two animals transferred to Merlin, staring at Harry with their large eyes. Tonks and Merlin were gazing at Harry; he felt angry and embarrassed that he had been discovered in such a ridiculous position. Silently, Merlin handed him back the Invisibility Cloak.

"Was it Malfoy?" Merlin guessed.

"Yes," Harry said bitterly. "Thanks for… well…"

"No problem," said Merlin, without smiling.