This is a Harry Potter/Merlin crossover. Summary: Saving the world is never an easy feat. Two teenagers set out to find the secret to defeating Voldemort. Their plan: nargles, a special spell and a trip to Camelot.

Pairings: Neville/Luna, Merlin/Arthur.

Enjoy!

~*~OoO~*~

A Special Spell

His eyes lit up. This was it! He could feel his heart beat in his anticipation as he could practically see the pieces come together. He had a plan. He could save the wizarding world. All he needed was an ally, someone who would be prepared to help him no matter how outrageous and dangerous the adventure would be. His mind flashed through all the people he knew. All of a sudden he froze and his face broken into a huge brilliant smile.

Neville Longbottom headed to the floo, knowing that Augusta Longbottom was out having tea with her friends.

He knew exactly where to go.

~*~OoO~*~

"What!" Luna exclaimed, the normally confusing girl was the confused one this time. "Say that again, slowly."

So Neville did, starting his story from after the battle at the Department of Mysteries.

Neville had gone to the room of requirement, hoping to work on his spell accuracy. He had remembered the moment when instead of disarming one of the death eaters, he had disarmed both the death eater and Harry. He had been sure that mistake would give him nightmares forever and Neville wanted to make sure that such an error would not happen again.

It was late at night. Neville had expected the room to be empty so he was started to find Harry inside, alone. It looked as though Harry had been quiet. So, Neville being the kind and caring friend he was, sat down and offered what comfort he could.

In the end, Harry had told him everything. Harry was scared. He didn't think he would be able to defeat Voldemort. Yet, he also didn't want to die by Voldemort's hand. He almost incoherently told Neville about the prophecy "The one with the power to vanquish the Dark Lord approaches..." But most importantly, "But he will have the power the Dark Lord knows not..."

Hence, when Neville went home for the summer holidays, he decided to search for possibilities for the 'power the Dark Lord knows not..." He had gone through his grandmother's libraries. The Longbottoms had always been a traditional light family and Neville was sure that Voldemort (yes he could use his name) would not know of anything in those books. This was how Neville stumbled across a text which was sourced from the Arthurian times. It told of how when a witch or wizard was in dire need of help and were inarguably of the 'light side' they would be able to get assistance from King Arthur and supposedly Merlin himself. The book didn't say exactly what this form of assistance was but the spell was fairly simple and in Neville's mind, at least worth a try.

Neville finished telling his story. There was a moment of total silence as Luna stared absent mindedly at the ceiling and Neville wondered if he may have to say his story for the third time.

Suddenly, Luna's eyes snapped into focus. She grinned.

"I have conferred with the nargles." She stated. "And I'm with you Neville – let's do this."

Neville followed Luna over to a small desk. It was shaped like a golden tree, with the branches sprawling out as seats. Neville thought it resembled one of the plants he'd seen in the newt level greenhouse. It was beautiful. Or in other words, it was really really cool.

Neville sat down and immediately, the smaller branches seemed to wrap around him, giving him a sense of homeliness and warmth. Neville was momentarily stumped and although the book was put down, Neville made no move to open it up to the correct page.

"The chair's enchanted." Luna said, noticing Neville's preoccupation. "It's designed to make friends feel welcome and enemies feel the need to run away screaming. It also wards off mistletoe." Here, Luna shuddered delicately and Neville laughed. "They can be awfully scary when they turn up at night."

Neville nodded as he recalled the mistletoe that would appear out of the many hidden corners of Hogwarts during Valentine's Day. He made a mental note to enquire about the precise nature of the spells later. Neville opened the book and leafed through to the required page. He passed the book over to Luna who simply put on a pair spectrespecs and read through the few paragraphs of information.

"Alright" Neville said once she was finished reading. "Do you want to do the spell or should I?"

"You should." Luna replied without appearing to take a breath. "You're good at charms and I'm sure you'll be able to do something like this."

Neville felt his cheeks pinken marginally with the praise. To hide his embarrassment, Neville looked through his pockets for his wand. He took Luna's hand; it wouldn't do for her to be lost in the enchantment. The blonde girl smiled at him in gentle encouragement. Neville took a deep breath and cleared his throat.

"Bonus rex rgis ego postulo lux lucis" Neville murmured as the tip of his wand lit up. Good king, I need the light.

For a moment, nothing happened. Some fluttering beacon of hope inside Neville wanted to die.

Then there was a bright flash.

Once the glare faded, Neville and Luna had disappeared, the book still lying upon the table.

~*~OoO~*~

It was like someone had decided to combine a portkey with a side-along apparition. Neville felt himself getting sucked in by the ancient magic. He felt as though his stomach was being squeezed and his brain cells being jumbled as the magic tried to determine whether he actually fit the requirements of using the spell. Neville's heart seemed to jelly; he found it difficult to breathe and he gasped wildly but he couldn't take in any air.

Then, suddenly, the magic released him. Neville appeared half a foot above the ground where he subsequently fell and collapsed onto a distinctively stone floor. Neville saw stars. A hand appeared in his field of vision. Neville clutched at it gratefully allowing Luna to pull him to his feet. Luna looked unruffled. Clearly, like riding thestrals, Luna found even the most bizarre forms of magical transportation easy.

"I wonder where we are…" Neville mused. He had no idea; the book seemed to forget to detail the fact that the spell caused transportation to another place.

Luna had no such confusions. "Camelot." She said simply and when Neville did a double take, she merely pointed towards the red caped knights which could be seen in the distance. Neville realised that she was probably right. The image did closely resemble a diagram he remembered from History of Magic, covering the times of Merlin.

Neville ducked his head around the next corridor. He knew the spell was supposed to give him help. All he had to do was find this help...

Neville expected many things but what he saw was not one of them...

~*~OoO~*~

"Merlin, I keep telling you I love your magic but that doesn't mean you have to use it at every single second." Arthur said as he walked with Merlin half a step behind. "Yes thank you but my shoes are polished enough already!" Arthur snapped.

He turned around angrily only to be met by Merlin's bemused and cheeky grin.

"Sorry Arthur" He said completely unapologetically. "There was a speck of dirt on them."

"Was not!" Arthur burst out scandalised. As his voice bounced off the loud ceilings, a loud 'crash' could be heard. If either Merlin or Arthur had been listening carefully, they would have realised that the sound wasn't caused by the knights training but in fact be people falling heavily to the ground. They may have also noticed that the sound wasn't a distant echo but from just around the next corner. However, both men were distracted because Arthur had Merlin in a headlock and was trying to wrestle the dark haired warlock into a wall.

For all intents and purposes Merlin was putting up a fight. His eyes would flash gold and the king's shoelaces would untie, causing Arthur to momentarily stumble. Or sometimes Arthur's arms would reach out when a sudden gust of wind would cause him to lose his grip. However, for Arthur and Merlin, this was a game which ended with Merlin pinned and Arthur smirking as he breathed heavily into Merlin's face.

"Prat." Merlin would huff indignantly.

"Sore loser." Was Arthur's ever efficient reply.

"You know you love me for it."

"Yes Merlin, that I do."

~*~OoO~*~

Neville, brought up in a string wizarding home, froze at the sight. He could recognise King Arthur. Although the textbooks had portrayed Arthur with more grey hair lining his fair head, Arthur looked more or less the same. Merlin too was easily recognisable. He was the most famous name in history. His face appeared on chocolate frog cards worldwide and there was no way Neville (an avid collector) could have missed getting Merlin's. So, no, it wasn't the shock of seeing two brilliant individuals that had him so stumped.

It was the fact that their bodies were pressed closely into one another. It was the fact that they stared into each other's eyes and whispered like a pair of devoted lovers that made his mouth open but no sound come out. Neville knew he urgently needed to find something to help Harry but he couldn't find the will to disturb such a beautiful and tender moment.

On the other hand, Luna had no such reservations. She moved to stand next to Neville. Without even blinking at the couple before her, Luna pointed above their hands.

"Oh look! A Blibbering humdinger!" She cried out.

Neville cringed. He tried to pull Luna back around the corner but it was too late. Arthur and Merlin broke apart and stared in their direction. Arthur's face coloured angrily and he looked set to call for the guards. Neville wondered if he was going to die, some thousand years before his real self was due to be born. However, he saw Merlin put a hand on the king's shoulder; Neville calmed as he saw Arthur visibly relax. Merlin stepped in front of Arthur, assessing them.

"You have magic." Merlin said confidently. "Yet you bring us no harm."

Arthur's calm suddenly vanished. "What are you doing here?"

The dual intense gaze of both Arthur and Merlin floored Neville. What could he possibly say that wouldn't leave him to be executed and burned at the stake?

Thankfully, Luna saved him from the dilemma.

"We are here to help a friend defeat a dark wizard." Luna answered. "And the nargles have led us here because you will be able to help us."

Merlin's brow furrowed. He had never heard of nargles (or blibbering humdingers) in his life; he made a mental note to ask Gaius later. Arthur's brow was also furrowed although he seemed no longer as angry as in a minute ago. Luna poked him hard in the ribs and Neville took this as his cue to speak.

Neville summarised the entire war, glad that Merlin and Arthur were paying close attention although Luna had drifted to the window and appeared to be in a different planet, entirely. Neville reiterated how Voldemort had been vanquished when Harry was a baby yet he returned to life later on. Neville briefly described the horrors the wizarding world had endured, the deaths and property damage. Then, Neville spoke about the prophecy and how desperately they needed 'the power the Dark Lord knows not'. Then, Neville had waited with baited breath as Merlin and Arthur pondered.

"So he was resurrected using dark magic?" Merlin confirmed and Neville nodded. "Well, in that case he has used a resurrection ritual and claims no physical body. His body is merely a construction of the magic manifested through the use of dark magic."

"What does that mean?" Neville and Arthur asked simultaneously.

Merlin opened his mouth but an airy high pitched voice interjected. "If we vanish Voldy's magic, he will become a squib. But because he has no body, he can't become a squib and then he will die." Luna commented, now watching the pigeons through the window. "It's like when the wrackspurts start eating oak trees and the trees..."

Neville poked her elbow, cutting off Luna's explanation about wrackspurts (by this stage, Merlin was shaking his head in wonder at how many magical creatures he had never been told about).

"Anyway", Merlin continued. "There is a very old, an ancient spell, and a variant of the banishing spell. It essentially strips away one's magic before purging all traces of that person's magic. For example if your dark wizard had enchanted someone to be their follower, that follower would no longer be compelled to serve. The spell requires a person with a lot of power."

"Harry is definitely powerful." Neville commented.

"And it also needs a just cause." Merlin stated. "It is a protective spell and will only work if the banishment is designed to protect the common people. It will always work but only if these specific criteria are met."

And with that Merlin's eyes flashed gold. The information travelled into Neville's brain, able to be transmitted to Harry with merely a touch.

"Thanks" said Neville sincerely.

"Good luck" Merlin well wished and beside him, Arthur did the same.

It was then that Luna and Neville began to flicker. There was a bright flash of white light before the two vanished, speeding through time back to the Lovegood house.

"Well that was interesting," Arthur mused.

Merlin shrugged. Hand in hand, the pair walked through the castle, ready to terrify some of the knights-in-training.

~*~OoO~*~

This time even Luna couldn't escape an awkward landing. This time, Neville rolled his ankle and flew sideways, knocking Luna off her feet. They were heaped together onto the floor, arms and legs tangling together but somehow they ended up face to face. For a moment, Neville just lay, barely able to comprehend that he had found a way to destroy Voldemort.

"Thanks for doing this with me Luna." Neville murmured.

"Of course!" Luna chirped. "It was so much fun!"

And as they basked in the tangled sort-of hug, it was unsaid that should the need ever arise, they would keep going on outrageous adventures together. That's what true friends were for.

~*~OoO~*~

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