Hello dear reader and welcome to my first ever crossover! (and fan fiction for that matter). Before you start reading I just want to make some things clear. I'll be using the Harry Potter books, not the movies. That includes the years they are set in; 1991/1992.

Most of the story will be in Danny's POV, but I will be swapping POV to other characters throughout the story. I didn't want to write a carbon copy of J.K Rowling's book word for word with Danny just inserted into it, though I can't avoid that some dialogue lines or scenes will be quoted. It's unavoidable and I'll try to paraphrase them if I can.

Now, with that all said; Enjoy! And of course, Disclaimer: I don't own Harry Potter or Danny Phantom.

Chapter One: Mission Through Time.

This cannot be right.

Once more Clockwork reversed his viewing mirror back, watching as the images of time flew past. Then, it happened again. A key moment in time was being altered against his will. The Time Master frowned at the change, hand hovering over the mirror as it replayed. This was beyond not right; this was not possible! Time had been fine only mere moments ago, and yet now it was unraveling before his very eyes. He scowled, gripping his time staff tightly to let his power flow through. Tapping the mirror, he reversed it over and over again, shifting time through every possible outcome. Every pathway he could think of he viewed in the hope of finding the reason.

But every timeline was the same. The past, present, and future were morphing; evolving, into something different. He returned back to the source, watching a scene he had viewed a hundred times before. He watched the boy approach his fate. Watched their battle, the confrontation of the hero and villain. Light overcoming the dark. The correct course of the future.

Instead, the hero lay cold and dead.

In all his existence Clockwork had never witnessed a change quite like this. Never had he faced a change that he himself had not caused. It was too random, too cleared deliberate to be an error on his part. As he moved down time to watch the aftermath he only became more certain, someone or something was altering the timeline.

But that wasn't possible! He felt an odd fury at the very thought. He was the Master of Time! Only he and he alone could travel along the path of time. No other being in existence, magical or not, shouldn't have the power to travel through time so freely.

Moving down the timeline further he watched as the world would be destroyed bit by bit. The death of the boy would demolish all order and harmony that his victory had made, leaving in its wake misery and anguish to all. It was like Clockwork was watching Phantom's future once again as his future-self devastated the world. No, it was like the alternate timeline. Though different in natural the outcome was the same. Death, despair and the world without hope were being shaped back into reality. It was inevitable.

Closing his eyes, the Time Master paused the troubling images, shifting into his elder form. Slowly he turned away, vision wandering around his lair. His sight froze at the grey door that held the dented thermos within. How ironic that all that hard work he had done for Phantom was now pointless. No matter what he did now, Danny Fenton's future would change back yet again. No, it would be worse if the Dark Lord rose to power sooner. His family would die in the crossfire like the others and instead of living out a future of despair, Fenton would not even get the chance to exist.

Unless… raising his staff back to the mirror he brought the image of their first encounter back and concentrated, trying with all his might to correct the timeline directly. Purple energy swirled around his body, his eyes glowing brighter as he willed it to return. The mirror trembled, rippling back and forth as the Time Master gritted his teeth. At first, it seemed that he had succeeded, that the event changed back to its correct path. But whoever was responsible had caused more damaged than Clockwork had thought. The image changed back to the dead boy, the Dark Lord gleefully holding the stone in triumph.

He growled and slammed his staff into the ground, the mirror turning back to swirling green. The echo of his staff rang through his mind as he tried to calm his emotions. Anger wouldn't help here; what he needed was a plan. With a sigh Clockwork glided to his window, arms crossed as he gazed out into the vast ghost zone in thought. He couldn't fix the timeline here, nor could he dare risk fixing the timeline in person. The Observants would never allow him to. He groaned as he shifted to his child form. Of course, how could he have forgotten the Observants! Once they got wind of the change all hell would break loose and those fools would make things worst with their laws. He needed to fix this issue in a way that he could limit the cost it would cause for all of them.

Phantom. He frowned at the thought, fingers tapping on the metal of his staff. The young half-ghost? Too risky… and yet he could think of no one better. But he had proven to them how dangerous he was to the timeline, sending him back to the past would be an unwise idea. Not only that but whatever had caused this was strong, maybe stronger than Phantom. Instead of saving everyone from doom Clockwork might end up sending the teen into a den of wolves. Sealing his and the boy's fate. But right now, it was his only choice. The Time Master would once again have to take that gamble.

Realizing that he needed to move quickly for his plan to work, Clockwork grabbed one of his Time medallions. With a twirl of his staff, he teleported out of the Ghost Zone straight into one of Casper High's classrooms. In half a second he hovered in front of the class. A blur that no one, not even the teacher who Clockwork teleported in front of, saw. Even Phantom with his ghost sense could not react fast enough for him to notice.

"TIME OUT!"

With his words, the world froze in time. Clockwork drifted through the class, looking down at the medallion in his hand with a frown. Ironically, he didn't have much time till those pesky Observants figured out his plan. Once they sense that he had left his tower they would certainly find out. And he certainly knew they wouldn't understand his plan to use Phantom to repair this. After all, in their eye Phantom was a threat to all of time. Using him to repair it yet again would sound outrageous to them, especially since he had almost destroyed the future twice and helped create a being to exist outside of time.

He drifted over the children to the back of the room, stopping in front of the half-ghost. Amity Park's ghostly protector had a look of boredom etched on his face as he gazed out the window, clearly lost in his own thoughts. For a moment the Time Master stared at him, noting his eyes were heavy with dark circles. The teen had always looked tried, right up to when they had first met. But after facing off against his evil future self a different kind of tiredness had settled there. Content as he was to have saved Phantom's future, Clockwork knew he wouldn't be the same after that fight. At least, not for now.

Looking up he observed the room, noticing the person behind Phantom. Tucker Foley was leaning forward with a cheeky grin on his face, about to make his best friend's day worse. He had already seen what would happen. Phantom would cry out in shock at the touch, too lost in his mind to realize it wasn't a ghost attack. He would be told off by his teacher for disturbing the class, laughed at by his peers and given lunch detention for his actions and sarcastic response. Sam Manson would become angry at Foley and the trio would be troubled for the rest of the day. The natural direction of time.

But Clockwork was about to change that.

With a sigh he reached up and looped the medallion around Phantom's neck, waiting for it to take effect. At first, the teen didn't seem to notice that time had started once again for him. He huffed his dark bangs out of his face and continued to stare out of the window. Abruptly he frowned, finally realizing that Mr. Lancer was no longer ranting. Lazily he glanced over to the teacher only to come face to face with the ghost. With a yelp, the Danny jerked out of his seat as his ghost sense exploded from his mouth in a puff of mist. He tripped over his chair, landing on the ground with a heavy thud and a clatter. Clockwork chuckled as the teen tried to untangle himself from the chair, staring up at the purple-robed ghost with disbelief.

"C-Clockwork!?"

The Time Master chuckled again, tilting his head in amusement. "It's been a while, Danny Phantom."

Danny could only stare at him in shock, not able to believe the Time ghost was seriously right in-front of him. But when it became clear the ghost wasn't about to vanish in a puff of smoke he slowly got up, propping the chair upright as he went. Nervously he smiled back at Clockwork.

'Four days to you is 'a while' then?'

"For me, everything is 'a while.'"

"Right…" Scratching the back of his neck Danny sat back down, finally noticed that everyone in the classroom was unmoving and quickly he looked down to see the Time medallion on his neck. "So, you've saved me from Maths. I would say thank you and all that but- wait, what's Tucker doing?" He had turned right around, only to come face to face with Tucker's pointing finger.

"I believe he is about to poke you in the back."

Danny scowled at his best friend. "Seriously?"

While the teen was busy muttering about the payback his friend was getting after this Clockwork shifted to his elder form, toying with the gear in his staff. Time was too short. And now that the Time Master was facing Phantom, he was quickly having doubts about how to tell this proposal to him.

"Tucker's not about to cause some sort of catastrophic event like I did with the C.A.T test, is he? It would explain why your…here…"

He watched as Clockwork continued to twirl the gear in his hand, a grim look settling on his pale face. A sense of dread filled Danny. Whatever the ghost had to say it couldn't be good. "You didn't just come to chat, did you. Something really bad has happened again, hasn't it?"

The ghost sighed, shifting his form again. Gently he placed his staff on Phantom's desk, hoping the space would stop him from becoming distracted. "You are right Phantom, something bad has indeed happened."

Danny slouched in his seat. "Okay, what then?

Clockwork paused, thinking of the words to say to him. "…Simply, I am here because what has transpired in the past is now affecting the future. I am here because the timeline has begun to change."

Eyes widening Danny shot up in his seat, staff rattling as he slammed his hands on the table. "Wait a minute! Are you saying that the timeline has changed, like in changed in a good way? Or like evil-self-destroying-the-world change?"

"It's more like a key moment in time has been altered. And due to that change, the whole world's future has fallen into chaos, your future included."

"Then you mean…then you mean that my self has broken out and, and-"

Danny struggling with the thought of his evil self-returning. He'd only been able to stop him because he had the element of surprise with his ghostly wail. Who knows if he could defeat him in a second round? He felt his pulse quicken, his breath hitching in his throat at the thought of his nightmares coming true. But when he looked up at Clockwork he was amazed to find the ghost quite composed.

"No. This has nothing to do with your evil self. Your future in that regards is safe."

The ghost could see the tension melt off the teen's shoulders. Danny sighed deeply, a weak smile appearing on his face as he slumped back down. Relief that Clockwork did not share.

"No, in reality, this is much worse than that. Someone has gone back in time and reformed the past, changing it so that the world will end up being destroyed."

"What? I thought you're the only ghost that can control time?"

Clockwork looked down at his chest, watching the pendulum tick back and forth. "At directly viewing the timeline I am. I see every outcome and path, and control it." He gestured to the classroom. "No other being in existence can stop time as I can. But saying that there are indeed humans who can change time and in turn travel back." Clockwork morphed to his adult form and with a smirk pointed to the medallion around Danny's neck. "There are more of my medallions in the world of the living than you think. My earlier creations started off much weaker than the one you wear, so I don't worry too much about them."

"There are other people who can time travel!" Danny held up the medallion suddenly seeing in a whole new way. "Wait, Clockwork, you mean that there are people who have a time medallion just like this? Isn't that still, I don't know, kind of dangerous?"

"Only a few are in possession by others. Besides," Clockwork shrugged in a bored manner, looking out the window. "those who do have my medallions know the cost if there alter time. It's their own responsibility if they wreck their time. Not mine."

"Oh…" Danny said awkwardly, let the medallion fall from his hand. He watched as the ghost switch through his ages before settling back to his adult form.

Clockwork's pupil-less eyes narrowed as he continued to stare outside. "But this isn't due to one of my medallions. Someone has physically gone back in time and changed a key event. It shouldn't be possible, but… it has. Thankfully the existing timeline has not begun to change just yet, but soon…all timelines will adjust and this world will be nothing more than a wasteland."

Danny paled. "I really don't like where this is going,"

Clockwork turned back to regarded the teen as he hunched lower in his seat, chin almost touching the surface.

"-Or what all of this has got to do with me."

With a sigh, Clockwork began to explain his plan. "I need your help Phantom, because like it or not this change will affect you too. See, if we cannot fix this changing of time at its source and the effects of the shift take place, you would no longer exist."

"Huh?" Danny blinked, baffled. What did the Time Master mean he wouldn't exist?

The ghost closed his eyes and took a breath. He needed to tell the teen what was about to happen without panicking him. If he panics, there was a chance Phantom would refuse to help. But before Clockwork could speak Danny seemed to come up with his own conclusion.

"Oh! You mean I won't become a half-ghost? I admit that's going to suck. But being normal again will be nice. I can finally get some sleep instead of worrying that the Box ghost is going to show up and yell 'Beware' in my face-"

"Danny," Clockwork said gently. He bowed forward, picking his staff up and pointing it to his forehead. "You would not be born."

Danny frowned at Clockwork, struggling to understand what he had just heard. What did he mean he wouldn't be born? Was that even possible? He still didn't understand everything about the time stream and this time travel stuff. All he really knew was that messing with it was dangerous. Very dangerous.

"Don't tell me Plasmius has found a way to time leap and adjusted the future to marry Mom or something?" Danny chuckled weakly, hoping that was the worst of it. But Clockwork shook his head.

"No Phantom, Vladimir has nothing to do with this time change. If it was that easy I wouldn't be asking for your help."

Danny felt his heart jumped into his mouth. This was bad. Worse than evil-self-destroying-the-world bad. He wouldn't have a chance to muck up his future in the first place. But still, he didn't understand how he could suddenly not exist. Or more like he thought he knew; he just didn't want to say it out loud. He wanted Clockwork to confirm it himself.

"How…" Danny muttered, catching the ghost off-guard." How come I won't be born in this new timeline?"

Clockwork closed his eyes, picturing the scenes in his mind. "There is much… much you must understand to answer that, but I do not have the time to stand here and explain it all. Basically, thanks to this change a very cruel man will rise to power. A world war will break out because of this man, a war that is like no other. Powerful forces with magic at their command will capture the world bit by bit. They start in Europe, then a year before your birth they will turn their sights to America. Your parents are involved in the conflict and will be killed in the crossfire."

Danny gulped, his mouth going dry. It was worse than he had first thought. Both his parents would be dead. But then he realized that Clockwork had only mentioned his parents.

"Jazz!" in a panic he looked up and grab the hem of Clockwork's cloak. "What happens to Jazz!?"

Clockwork twirled his staff, worried that they were running out of time. "She will be one year old at the time of your parent's deaths. Because of this, she is orphaned and, well, I amuse you can guess the rest."

If Danny wanted to save his family before, it was unbearable now. His sister would end up alone in a world torn by war. It was worse than Danny could imagine, no little brother, no Mom, or Dad, nothing. Pure fury raged through his body making his eyes flashed neon green. No way was he losing his family again! Not after all he had done to save them only days ago. He stood trembling, not in fear but determination. There was no question in what he had to do.

"Okay Clockwork. I'm guessing you've got a plan to save the world, so tell me what you want me to do."

The Time Master couldn't help but smile. Even though the situation was dire, he could not help feeling proud of Phantom selflessness. His own life was on the line and yet his only thoughts were on saving those that he loved. That was the thing that the Observants could never see about the young half-ghost, the reason that Clockwork had given him the second chance in the first place.

Shifting his staff Clockwork held his right hand out to the teen. "Quickly, we have much to do and very little time to do so."

The teen nodded and took the ghost outstretched hand. "Going Ghost" He smirked, and with a surge of blinding white light rings wrapped around his body. As they broke apart black hair turned snow white as Danny became Phantom.

Clockwork laughed despite himself and swiftly teleported them out of the world of the living to his lair in an instant. Danny shuddered at the gust of mist that escaped his lungs, his ghostly body startled at the atmosphere change. Once Clockwork was sure they were alone he took the medallion from his neck, quickly leaving the young ghost to return to his mirror. He was hoping above all hope that the Observants had not yet caught on to his intentions. Danny shivered again at the chill that rushed through his chest, gazing around the Clocktower in awe. It was still as freaky as he had first thought, what with the constant ticking.

With a shake of his head, Danny flew over to Clockwork, watching him summoned images on its surface.

"So…. What do I have to do anyway?"

The Time ghost stopped and turned to him, a curious look crossing his face. "What do you know of Witches and Wizards?"

Danny snorted with laughter. "That they have pointy noses, warts and fly on broomsticks with black cats? Not much."

Clockwork couldn't help but snicker. "So, in other words, you do not believe they exist."

"Pretty much…Wait, you're saying that Witches and Wizards actually exist? So that "magic force" you talked about is a bunch of witches going all out and turning people into toads."

"Not quite, but yes Phantom, they do exist. They are a type of human that is connected to the flow of magic."

"Magic…" The teen frowned, looking at the old ghost. "so there are other people who have supernatural powers like me?"

Clockwork turned to him, a strange look plastered on his face. "Not just humans. There are entire species of creatures and abilities that exist around the world." He smirked. "Did you really think that we ghosts were the only beings of legend to exist? There are countless others, Phantom, all hiding around us. In both the living realm and the ghost zone. Even in realms beyond that."

He raised his time staff, making images swirl on the glassy surface of the mirror. Placing a hand on Danny's shoulder he moved them closer, words almost at a whisper like it was all some very important secret.

"Those born with magic in their veins, or Witches and Wizards as they like to call themselves, are born all over the world from every race. Some are born from the blood but many are born without magical parents. They live in their own little world, like you, parallel to the humans without the magic gift. Over centuries of practice and caution, their kind has been able to hide from the world, much like us ghosts did before your parents made the portal and allowed free travel. Though the magical world has known of mine… our kind for quite some time, as many of us like to journey whenever we can into theirs."

"So, you're saying," Danny breathed." That right now, there's a whole race of magical people living under everyone's noses?"

Clockwork nodded.

But Danny's brow furrowed. "But- but that can't be right! You can't tell me that these people can just stroll around the world without at least a few people getting a little suspicious of them!"

"Phantom, they are ready for occasions like that. Memory wiping, changing events to look like illusions or weather disasters and even public and political corruption. They have thought of it all and thanks to that, have remained hidden." The ghost chuckled. "Well, mostly hidden."

Danny didn't understand what he meant, and Clockwork tapped the mirror. An image of a woman struggling as she was tied to a tree appeared, people surrounding her with touches as they edged closer.

"Witch burning…" he whispered and the Time Master nodded.

"One fatal error of a foolish woman caused years of prejudiced for their kind. Unpreventable."

But to Danny that just left him more questions. "If we don't stop this event from being changed, then the world will be taken over by these magic folk-"

"No." Clockwork cut in. "The magical world will be in just as much war as the humans will be, brother will turn against brother."

He gestured to the mirror again where Danny saw a group of masked people. In front of them was a pale looking man whose eyes were rimmed with shadows. "In the past, years before the event change, there was a villainous wizard, more of a necromancer if anything. This man slowly began tearing the magical world apart, so much so that even the Ghost Zone began to notice the changes. There was so much terror and death Phantom, you could only begin to imagine how hard it was for me not to change that timeline, to merely watch that kind of torture and death. So many ghosts joined our realm in those years, but…all was as it should."

Clockwork closed his eyes in thought briefly before continuing "This man kept killing, again and again till he was no longer could be called human, till his humanity was washed away and all that was left of him was a monster. However, in a rage at learning of a prophecy that would destroy him, he went to kill the baby that would turn into his slayer."

"He went to kill a baby?"

"Yes, but he undervalued the powers of the baby's mother. For she was a strong, kind-hearted witch and had a power that the man could never truly understand. She shielded her child and the killing magic rebounded back to the man. Yet he did not die. He became neither living or dead, but a mere shadow, a shade weakened but hell-bent on revenge."

Clockwork turned and grip both his shoulders, hoping he would understand the importance in his tale. "Phantom; this shade then weakened, overshadowed a human years later to find a way to a revive itself. Only for it to be stopped by the very child he tried to kill all those years ago."

"That's the incident, isn't it?" Danny stated. "The event that got changed."

"Yes. Someone has gone back in time and change that exact moment. Instead of the boy stopping the shade from becoming physical again, the boy is killed and the most malevolent wizard in all history will return."

Danny whitened as much as his ghost form could. "So… that's what we need to do? Stop this shade from killing this boy?"

"You need to stop it."

The ghost pointed his staff yet again to the viewing mirror, a picture of a dark room appearing. "I am going to send you back in time. To the year 1991, to stop the death of that boy. I have viewed countless ways and possibilities and this is by far the safest one I can see. I wish…there was an easier way, but I cannot tangibly affect the time stream. So you Phantom will do it for me. You will become my catalyst."

"Wait! You're sending me back to 1991!? That's like-" Danny quickly ran over the years in his head. "-Twenty years in the past!? There'd be no one there I'll know, I'll be-"

He stopped, realization dawning on him. "Alone."

"Phantom." Clockwork sighed in repose to his panic. "True, you will be alone, but you do not have to do this alone. Others at the school can help you in your task."

"It's just…School?" astonished he glared up at Clockwork, floating away from him. "You pulled me out of class just to send me back in time to go to another school?"

The Time Master laughed at his childish response. "It is a school for witches and wizards, and as fate chooses it, the place the shade will come to kill the boy."

"I don't care if it's a school for ghosts; it's still a school!"

"You don't actually have to take classes, you're not a pupil there."

Danny huffed muttering under his breath. "It's still a school…" Clockwork ignored the troubled teen and looked back at the mirror.

"It might pain you to be there, but out of all the ghosts that I know, you are perfect for this task."

"Yeah? Is it because I'm just such a nice person?"

"No, it's because of your transformation."

Danny gave him a puzzled look, not getting it. Clockwork decided to wait, hoping the boy would figure it out on his own.

"Transformation…" the teen suddenly groaned, slapping his forehead. "Of course! Because I can still use my ghost powers when I'm normal, I can hide in plain sight and still use my powers."

"Exactly. You don't need to hide in the shadows as your human form will protect your powers from any detection, at least to those not expecting it. Also, since you are young, no one will think otherwise at seeing a teenager running around the school."

"Perfect..."

Clockwork watched in amusement as Danny huffed angrily about. But even though the Time Master knew he could blend in easily at the magic school, he knew that there would be others there that could find out about his abilities. The timeline was going to change into something new no matter was he did, so the Clockwork thought best to prepare Phantom for the worst.

"A word of warning; be watchful who you reveal yourself to. Once I send you back, I cannot help you directly. Who you decide to grace with the knowledge of your powers is up to you, but be careful who. Some might not take kindly to your…uniqueness."

"You mean there are people who would love to dissect me there as well? Great."

"Phantom, I don't think you understand the gravity of your powers-"

"CLOCKWORK! HOW DARE YOU!"

Both froze at the booming voice that echoed around the lair. Clockwork hissed, his eyes flashing red and for a rare moment, his anger emerged.

"Blasted Observants! They are not as naïve as I take them for!" The ghost grabbed Danny's jumpsuit and gently tugged him towards the mirror.

"Now go."

"But what about you!?" Danny hesitated in front of the portal. He knew he had to do this, but deep down he didn't want the Time Master to be in trouble because of him. That, and he was now starting to doubts that he could actually do this.

The Time Master smirked in reply. "I will be fine, they cannot hurt me, but they can hurt you."

But as Danny went to pull himself through the portal, he didn't feel Clockwork's grip loosen. Concerned Danny looked back to see Clockwork scowling at the mirror, a strange, almost pained look on his face. It was strange to the teen; Clockwork had always appeared to be such a composed ghost, like no matter how dire things got nothing could ever faze him.

"One more thing. I believe the individual who changed the timeline will be there with you. I do not know who they are, whether human, ghost or...something else. But know that they likely try to stop you. So Danny…" Clockwork pulled him closer, almost whispering his words. "Do not get yourself fully dead; it would be hard even for me to correct that."

Danny felt a shiver at those words. Something about them told him the one who had changed time wasn't somebody to mess around with. They meant business. And if Clockwork, the most powerful ghost Danny had ever encountered was nervous of them; then what chance in hell did he have?

The teen merely nodded, trying to hide the sick feeling that had just settled in his stomach. The old ghost only gave him a weak smile in return. However, just as he was about to ask him something else Danny quickly caught sight of the Observants behind Clockwork, flying madly towards them.

"STOP RIGHT THERE CLOCKWORK! HOW DARE YOU DISRUPT THE TIMELINE AGAIN! YOU–"

But Danny never heard the rest. Clockwork pushed him into the portal and closed it immediately, leaving him alone.

Just a quick note: if there are any grammar error's please let me know. I'm still learning creative writing and I am curious in opinions on how I write. Any feedback would be helpful.