I've actually been working on this story in bits and pieces since I was in high school over five years ago.

Summary: Voldemort has a new ally, someone even worse than him. The only one capable of defeating this new enemy is a muggle ghost named Danny Phantom. Will Danny's help be enough for the Order to win the war? Or is Harry doomed to become just like Voldemort? A killer.

Chapter 1: New Allies

Red eyes met an identical red. Both evil and malicious. Although one pair seemed more so than the other. The man, if you could call him that, with the slightly less evil eyes looked at his 'guest'. A cruel smirk played across his lipless mouth. He was an extremely pale man with no hair, slits for nostrils, and dark narrowed eyes. His 'visitor' was completely shrouded in darkness, his glowing red eyes the only visible feature.

Voldemort smirked at his guest, though he tried to hide the uneasy feeling in his stomach. He had only experienced this feeling once before; two years ago in his father's graveyard, when his and Harry Potter's wands connected, bringing the spirits of the dead forth temporarily. He contemplated the irony of the situation as he gazed at his guest.

"So you are the one I was told could aid me in my mission?" His high, cold voice echoed in the empty chamber. He could not see his 'friend's' face but he knew he was smirking.

"Oh yes." Unlike Voldemort, his guest had a deep voice that made Voldemort hide a shudder. "I can get rid of your pest. Only," Voldemort's smirk dropped; the catch, "if you can get rid of mine."

Voldemort blinked. "And who is your pest? Surely there is no one as strong as you." He spat. Loathed as he was to admit it, Voldemort knew that if his guest so wanted, he could kill him before Voldemort even reached for his wand.

His guest laughed. A deep, resonating laugh that seeps into your soul. "Oh, but there is. His name is Danny Phantom."

Voldemort's lip curled. A name like that could only belong to a teenager, and a muggle no doubt. It seemed as though he and his guest had more in common than he previously thought. "And who is he? How is he so powerful?"

His guest finally came into the light, allowing Voldemort to see him for the first time.

His guest was pale. Paler than Voldemort. He was so pale he looked as though his skin had a bluish tint to it. He had sharp fangs, giving him a vampire look. A forked tongue slithered between his lips. His 'hair' was actually blue fire. His ears were pointed and his eyes glowed a sinister red. As if his face wasn't bad enough, the rest of his ensemble only added to the evil look. He wore what looked like a black and white jumpsuit that clung to him like a second skin, showing off his bulging muscles. He also had a black and white cape with a pointed bottom. On the center of his chest was a white D with what looked like a P on the inside.

The 'man' smirked. "He is so powerful because," his smirk widened, "he used to be me."

Voldemort's eyes widened.

Dan Phantom's laugh echoed off the chamber walls.

~o0o~

Snape sprinted up the short steps and barged into Grimmauld Place. He was late for the Order meeting but the news he carried was far more important.

When he slipped into the kitchen he was not surprised to see Harry Potter, Hermione Granger, Ron, Fred, George and Ginny Weasley seated at the table while Molly Weasley fumed quietly in her seat. Dumbledore sat at the head of the table, the seat to his right the only one empty. Dumbledore immediately noticed his presence and stood up, drawing all attention toward Snape.

"Severus!" Dumbledore exclaimed, a relieved smile across his aged face. "I was not expecting you today. I was under the impression you had a different meeting today." His eyes, missing their usual twinkle, held worry for his friend. He gestured to the empty seat and Snape collapsed into it, feeling very tired.

He took a moment to look around the room, lip curling upon seeing Potter in the seat next to him. Potter in turn glared back at him. Weasley and Granger, Potter's sidekicks, sat on the other side of him. The whole Weasley clan, sans Percy, was here. His lip curled even more when he saw the werewolf sitting across from him with the pink haired Tonks on his left. Kingsley was here, which Snape was relieved to see as he actually likes the man. Mad-eye Moody was here, his magical eye watching Snape's every move. McGonagall was sitting stiffly next to him.

Snape turned his attention back to Dumbledore who had been watching him patiently. "The Dark Lord has given everyone new orders."

Everyone stiffened and glanced conspicuously at Harry, whose face hardened. "These orders also," Snape drawled, seeing their looks, "do not concern Potter, the Order, the Ministry, or the Wizarding World in general."

Everyone looked at him, stunned. Even Dumbledore was surprised at this news. Though it only made him more wary. What was Tom up to now?

Snape continued. "The Dark Lord, apparently, has a new ally." Everyone exchanged scared looks. "No one but the Dark Lord has even seen him. Although," he hesitated, "the Dark Lord seems to be afraid of him."

The Order gasped. If the Dark Lord was afraid of his own ally, what did that mean for them? Voldemort had only ever been afraid of three things: Death, Dumbledore and Harry Potter.

"According to the Dark Lord, his ally will only join him if we take care of a problem of his. He described this problem as a 'pest'. He even compared this 'pest' to Potter." Harry flushed when everyone glanced at him. "We were ordered to kill this person, no matter the cost. He lives in America, a small town called Amity Park." Dumbledore stiffened, catching everyone's attention. Snape ignored it, for now. "Our target is someone called Danny Phantom." Dumbledore paled.

Remus, not noticing this, spoke. "Then we must go and protect him before the Death Eaters get to him." People began to agree; nodding and murmuring their opinions. Dumbledore's strained voice silenced them.

"I am afraid that it is more complicated than that." His voice was slow and deliberate, but also strained, tense.

Tonks looked at him, baffled. Along with the rest of the room. "What is so complicated about protection?"

Dumbledore placed his fingertips together and gazed at the table, deep in thought. "The protection is not the problem. It is the location and the person in need of it."

Snape quirked an eyebrow. "Oh?" he drawled. "And why is that?"

Dumbledore did not look up. "Amity Park is considered a no-mans land for wizards." They exchanged puzzled looks. "It is known as the most haunted town on Earth." Hermione snorted quietly. As if a town could be 'haunted'! Ghosts were peaceful. Dumbledore shot her a look, causing her to redden as she realized he heard her. Harry and Ron smirked. "The ghosts that inhabit Amity Park are much different than the ones at Hogwarts. The ones at Hogwarts were wizards while the ones in Amity Park were muggles. Because they were powerless in life, they became powerful in death. The opposite happened for wizards. Muggle ghosts are very powerful and dangerous. When the muggles became aware of ghosts, the American Ministry tried to get involved. That was when we realized that muggle ghosts are immune to our magic." The Order exchanged worried looks. Immune to magic? "The Ministry then declared the town a no-wizard zone." It was silent for several seconds.

Minerva's voice broke the room's silence. "And what is the problem with the person we must protect?" Her voice was hard. She had a feeling she wouldn't like the answer.

She was proven right.

"Danny Phantom," Dumbledore said slowly, "is a muggle ghost."

The room erupted in whispers and shouts. The trio, as always, was conversing in low whispers. Others, like the twins and most adults, were shouting. A ghost?! Why would someone who was already dead need protection? How does Voldemort expect his Death Eaters to kill what is already dead?!

Minerva was one of the silent ones. She was staring at Dumbledore with a calculating expression.

"And how did you know he was a muggle ghost, Albus?" She asked suspiciously.

Everyone ceased talking at once. They glanced from McGonagall's narrow eyes to Dumbledore's slightly nervous face.

"Yes," Snape drawled, "I, too, was wondering how?"

Dumbledore looked at all the expecting faces and sighed. "The Hogwarts' ghosts sometimes travel to the world of spirits. Now commonly known as the Ghost Zone. It is another world parallel to our own, and is the home of all ghosts. Around two years ago the Hogwarts' ghosts came to me with news of the Ghost Zone. A new muggle ghost had arrived. Said to be the most powerful. His name: Danny Phantom." Dumbledore paused for a breath. Everyone was looking at him with awe at his story. He continued. "Only a few months after Phantom's arrival, The Ghost King had been released. The Ghost King was known as Pariah Dark, the most evil and powerful ghost in the realm. He ruled the ghost zone until he was locked away. When he returned he pulled Amity Park into the ghost zone, trapping them. He was after Danny Phantom; who never leaves that town. Phantom and Pariah fought viciously, until Phantom won. He locked Pariah back into his prison and took the key. When Phantom defeated Pariah he unknowingly took his mantle and became the new Ghost King."

Dumbledore stopped his story and waited for everyone to process it.

Most, if not all, were staring at him in astonishment. From the way Dumbledore described him, Pariah Dark was extremely powerful. Yet this Danny Phantom could defeat him? He must be an extremely powerful ghost!

Dumbledore sighed. "I am positive Voldemort knows Phantom is a muggle ghost, yet knows that Phantom can still be killed. And I believe I know why."

"But how?" Remus asked, confused. "You said muggle ghosts were immune to magic."

Dumbledore could feel his heart speed up as worry coursed through him. There was only one type of muggle ghost that could still be killed. And he was hoping he was wrong. Though it would explain Phantom's power as that type of ghost are always more powerful than most.

"I believe," he spoke slowly, "that Phantom is one of the really rare type of ghosts. I believe he is a Halfa." Blank looks were all he received so he elaborated. "A Halfa is an extremely rare type of ghost. I believe there are only two in existence. One, a very dangerous and powerful evil ghost, lives in Wisconsin. He also visits Amity Park fairly often and fights with Phantom. Phantom is the other. A Halfa is actually a ghost that is not fully dead –"

Minerva cut across him. "That's impossible Albus! A ghost is the spectral residue of someone who died! You have to be dead to become a ghost." Everyone, sans Albus, nodded in agreement. Dumbledore smiled.

"That is why they are so rare. A Halfa defies the law of nature. A Halfa, is someone who is only half dead. They are still human, but have the ability to turn into a ghost at will."

Disbelief was splayed onto every face as they digested his words.

"You mean," Arthur said slowly, "that there are two people in the world who can turn into ghosts when they want?" He asked, incredulity lacing his voice.

Dumbledore nodded, once more staring at the table as though it fascinated him. He ignored the questions and stares aimed his way. His mind was thinking up possible ways to include Phantom with the Order. Obviously Voldemort's new ally thinks of Phantom as his enemy, which makes Phantom a valuable asset.

Now all he had to do was to get to Phantom before Voldemort's Death Eaters do.

And he knew of two muggles that could help him with that.

~o0o~

Danny sank quietly through his ceiling, turning tangible once he was fully in his room. With a tired sigh a glowing white ring appeared around his waist, traveling in two directions, causing his black and white jumpsuit to turn into blue jeans and his signature t-shirt. He plopped onto his bed and ran a hand across his tired face. Between ghosts, school, family and friends, he rarely had time to sleep. Though now that his parents found out the truth he did get more rest then when he was 14. If he was honest with himself, it was the schoolwork that made him so tired. Now that the ghosts were under control, he actually had time to put effort into his work. Instead of getting D's and F's, he was back to A's and B's. The ones he got before the accident.

Danny glanced at his alarm clock and collapsed onto his bed with a groan. It was only 6:45 am! He pulled his duvet over himself, desperate to catch a few hours of sleep.

KNOCK, KNOCK!

His eyes snapped open. Someone was knocking on the front door. The only reason he could hear it was because of his super-human hearing. He pushed off his blanket and crept from the room. The reason he was so alert was because the only people who visit the Fenton household were Sam and Tucker, The Guys in White, and Vlad. He knew it wasn't Sam and Tucker because they wouldn't bother knocking. It wasn't the Guys in White because they would pound on the door, not the polite knocks he heard now. Vlad would just waltz in as though he owned the place, which in his mind he probably did.

He snuck down the stairs, seeing his mom grab the door handle just as he reached the bottom.

Standing in the doorway was the oldest man he had ever seen. He had long white hair, complete with a waist length beard. His sparkling blue eyes were hidden behind a pair of half-moon glasses. He wore long blue robes with purple boots. Another man was standing beside him but Danny couldn't take his eyes off the old man. As soon as Danny saw him all his senses reared up, causing him to tense. His instincts told him the old man was dangerous, despite his appearance. He had to fight down the urge to Go-Ghost.

Apparently something was said as the old man and his friend were suddenly being ushered into the living room. His mother turned toward him, probably going to ask him something, when she noticed his expression. She hurried over, her eyes reflecting her worry. She lightly touched his cheek and turned his face toward her; he had been watching the doorway their guests had crossed through.

"Danny what's wrong?" She whispered, not wanting their guests to overhear.

Danny's eyes were unfocused, as though his attention was only half on his mother, half on the people in the other room. "The old man…" he mumbled.

Maddie's worry turned to confusion. "Albus Dumbledore? He said he would like information on ghosts. Why? What do you feel?" she learned a while ago to always trust her son's instincts.

His eyes became more focused on her now. "He is not as he appears… he is dangerous." He whispered, his body still tense.

Maddie frowned and glanced at the doorway. She straightened up and started for their guests. Danny's hand clamped around her wrist in an iron grip, halting her advancements. She looked at her son with a confused frown. Danny wasn't even looking at her, he was staring at the doorway where the two men were, probably getting impatient. "I go first."

She was about to object, after all, Danny said they were dangerous. But she decided against it. Danny was technically the most dangerous thing in the world. He could handle it.

She nodded and followed him into the room.

Dumbledore was sitting on the plush cushion as he waited patiently for the Fentons. As the minutes ticked by he could sense his friend's impatience.

"Severus calm down." He spoke lowly to his companion. Severus glared at him, his onyx eyes glinting dangerously.

"Calm down?" he hissed. "They have made us wait for roughly ten minutes now! Plus we are on a very tight schedule."

Dumbledore smiled and in that moment a young boy walked in, followed by Mrs. Fenton. Dumbledore turned toward the teen and his greeting died in his throat.

It wasn't his looks. The boy had an all-around average look to him. With his black spiky hair and icy blue eyes, he reminded him of Harry slightly. He even wore baggy clothes. No, the reason he was staring at the teen was because of the power. Unlimited power emanated from him, rolling off him in waves. The power was carefully controlled and wrapped around him like a comfortable blanket, signifying that he was comfortable with the power he contained. Power, more than even Dumbledore possesses. Which made Dumbledore very wary.

The teen's icy stare bore into Dumbledore's own, causing him to fight down a shiver. He saw Severus sneering at the boy and had to fight down the urge to warn him.

Mrs. Fenton's attitude towards them did not go unnoticed. When she had answered the door earlier she was friendly and welcoming. Now she appeared wary and tense. Her eyes kept flickering toward the teen who must be her son.

"I'm sorry for the wait." Maddie apologized in a tight voice. Severus' sneer deepened. "This is my son, Danny." Danny gave no indication that he heard her, his sole attention was on them, though mostly Dumbledore. "Now, what is it you wanted?"

Dumbledore tore his eyes away from Danny, thankful for the invitation. "We have heard you are the town's resident ghost experts?" Maddie nodded, expression still wary. "Well, we were hoping you would help us find a certain ghost."

Maddie tensed, causing Dumbledore to raise an eyebrow.

"And what ghost are you looking for?" She spoke through tight lips.

"Danny Phantom."

What happened next happened too fast for even experienced eyes to see.

One second he and Severus were sitting on the couch, the next they were on their stomachs on the carpeted floor, their hands bound behind their backs. Maddie had a type of muggle weapon pointed at Severus while Danny simply stood in Dumbledore's line of vision, calmly.

Dumbledore's mind was racing. He knew the Fenton's were notorious for once hunting Phantom. This is until a year ago when they stopped. But why would they react so violently to someone looking for him? What changed?

Danny crouched down so that he was closer to Dumbledore's face. "And what do wizards," he spat out the word, ignoring Dumbledore's eyes widening, "want with him?"

Severus had ceased yelling threats, which he had started as soon as he hit the floor. Both wizards looked at the muggle teen with astonishment. Albus knew the Fenton's never had any contact with wizards as all wizards in America were monitored. So how did Danny know about them? Maddie, it appeared, was just as surprised as them.

Looking at Danny Dumbledore felt the pieces fall into place.

A Halfa – half human, half ghost. The immense power.

Danny Fenton.

Danny Phantom.

Dumbledore wanted to smack himself.

He sighed. "So, pleasure to meet you, Mr. Phantom."