Disclaimer: I don't own Castle, Harry Potter or any other fandom portrayed here.

Summary: In his early thirties, he woke up one day with no memory of who he was and he made himself into Rick Castle. Eight years later he is in for one hell of a surprise. Harry Potter Crossover (will include some other fandoms but deep knowledge of them is not needed).

I know this is an annoying long AN but please read or you might get frustrated with the story. Also keep in mind that this will be very AU for every fandom involved. So if you're not a fan of huge changes, this is not the story for you.

Warnings: I assume that if you are here you are familiar with the canon of the fandoms being portrayed here and I will not be explaining them other than what pertains to the story. You need to be very familiar with the TV show Castle and the Harry Potter books. Other canons I use such as the TV shows White Collar, How I met your Mother, BBC Sherlock and Modern Family and Lie to me need only a passing knowledge. You can totally understand the story even not knowing much about them. I won't be following their canon, I am just borrowing some characters and their characteristics so being familiar with them is good but not essential.

A/N: While this is a Harry Potter crossover, the focus is mainly in the Castle world. Which is why I decided to post here instead of in the crossover section. First, because the HP crossover section has so few stories that I don't even know if anyone checks over there. And secondly because Castle is more of an adult show, so I figured, that I should be aiming at Castle fans who may be Harry Potter fans or have a working knowledge than the other way around. You know, avoid the little kiddies.

To be honest, this whole exercise started as a White Collar/Harry Potter crossover. And since I am not a fan of OCs, when I decided I needed characters for that crossover I started rooting around the other shows I watched to 'cast', so to say, my characters. And that is why there are so many crossovers. I used them for surrounding cast.

Richard Castle is always on a sugar high. He is a child inside but he can also be surprisingly serious when the situation warrants. He is also loyal to a fault, always takes care of those he loves and always has their back and believes in them even when they push him away. He doesn't give up either. He was there by Becket's side all along until she came around to seeing him for who he really was. I can't help but see the similarities. James Potter was said to be a prankster, immature but he also became an Animagus while still in school for his friend. Had Sirius's back when Sirius needed a home to go to after he ran away. Saved Snape despite their enmity. Fought for what he felt was right. Stood steady waiting for Lily to see that he was more than just a prankster and ultimately gave his life for those he loved, his wife and child. Neither is perfect, but they are both good men with huge hearts. They are also physically similar. So when wondering who could be James Potter, Richard Castle jumped out.

So while the White Collar/Harry Potter crossover didn't really pan out I ended up really getting into the idea of the Harry Potter/Castle crossover where James Potter is not only alive but ends up being Rick Castle (yeah, I know, spoiler alert. But really you find that out like in the first few paragraphs). So be warned, he is the main character, not Harry. This is a story of how he deals with the betrayals he was dealt and reconciles his old life with his new one.

Like I said, since I am not a big fan of having OC's I decided to give me a challenge and pick characters from other fandoms that could fit the roles I needed. So this became an exercise on choosing who could be a good fit and an exercise on portraying characters I love like Sirius and Remus in the role of, not necessarily villains, but not perfect guys either and making their roles believable. I also cast Dumbledore on the villain side and that was a first for me since I've always liked him. This was a very interesting exercise, turning around these worlds I love so much while trying to get at least part of that new characterization from canon. (Understand this, I adore the Harry Potter world, but I needed to justify the move to the US, and thus I had to take the flaws of that world and magnify them.)

I at first thought of having Lily really be dead but then I ran into the problem of Rick/James remembering his grief right in the middle of his already super complicated relationship with Becket. So instead I decided that James and Lily would have already been separated. I am not making her a villain per se but just someone who wasn't ready to be a mother (a bit like Meredith. You can see that despite her absence Alexis loves her and she loves Alexis. The only reason I did not use her despite the perfect physical resemblance was because from what we know of Lily in school and her friendship with Snape I can't see her in the role of Meredith. So for this story Meredith doesn't exist and instead I chose someone else.)

I was also watching "How I met your mother" and had the crazy idea that Robin with her crazy love of guns would have been the perfect sister for Richard Castle not to mention the fact that I could just see him taking care of this family and yes, there is one more woman to drive him crazy. Plus I needed the plural. You'll understand what I mean later on

At first I toyed with Harry already being in Hogwarts but that didn't work with some things I wanted plus, like I said, Harry is not the main character here, and I didn't want to distract from Rick with Harry's story. So good news, he gets a family while still a child! In this fic he's nine-years-old.

The seasons or years from HP, Castle, How I met your mother etc. do not match the years they were aired or they were supposed to be but how I wanted them to be. I wanted Robin to have still been a teenager, just out of Hogwarts, when all went down. Someone who Rick would still think was young enough to go to college, but at the same time I wanted her to already be friends with the rest of the HIMYM gang when the story starts. So she'll be 28. If I am not completely mistaken that was season 3.

Just because I like drama I love the idea of this all going down just after Kate gets shot while she is off licking her wounds, because I always thought that was kind of selfish of her and I think that the fact that she wasn't there for Castle at a very crucial time in his life when he's been there for her always would drive home to her how she needs to change. So this is season 4 of Castle.

For this to work I had to change a few crucial canon details. For instance, Gina and Rick never dated or were married. They are just co-workers. Maybe frenemies. He's been in New York for only 8 years so I didn't think there was time in the five years before he meets Beckett for two deeply involved long-term relationships. And I felt Kyra was more important. That, however has opened room for an interesting misunderstanding on Kate's part which you will see later on. (Wink, wink).

Also, Storm Fall isn't the book he had just published in the pilot. I can't justify him killing off a series that has just a few years but I can see him wanting different characters because here he doesn't just write one book a year but several. So imagine he writes them mixed up, a Storm book, then a Nikki, then single one without a series. I want him to have the success he has already and I don't think that is so farfetched. The Harry Potter books themselves are proof. Before book one, JKR was unknown and by book 4, which all had been launched pretty close to each other, she was a worldwide phenomenon. If you think so, then just bear with me and as Nathan Fillion once said, suspend disbelief! Any other changes in canon that I feel need to be explained outside the story I'll explain in A/Ns when they show up. As characters from other fandoms show up. I'll give you a little explanation in an AN after the chapter. Because this An is already more than 1 k long. So let's get to the story! And sorry for the delay!

Oh, yeah. Also I've never been to NY so I've tried to use locations I've seen mentioned either on the show or other fics, or even Googling. If I say something too stupid New Yorkers, I apologize.

"The dad who lived"

Chapter 1 – The dad who lived

Richard Castle made his way to the door in a huff. He would have to have a serious talk with Eduardo. He couldn't just let people not on the pre-approved list up without buzzing them first. That was a short list and he knew for a fact none of them would be here now. Well, not for a fact. There was the one whose whereabouts were semi-unknown. Semi, because he did talk to her dad every week. He was worried. He had been suffering after seeing her almost die. He had forgotten what sleep was like, seeing as he was woken from nightmares of her dying just moments after closing her eyes. And he was just her friend. Partner. And he would like to say he didn't know how Jim Beckett would feel but he did. Because he may not know much about his life prior to waking up at Lenox Hill eight years ago but he did have that one awful memory. Of flames, and his little boy, whose name he didn't even remember, being engulfed by them. No father should go through that. See their child die. And if there ever was a reason for Jim to fall off the wagon that was it. So he made sure he didn't. He made up some story about needing to learn about baseball for one of his books and how Kate had told him Jim was an avid fan and had Jim take him to games or met him once a week to discuss baseball ever since Kate decided to isolate herself in his cabin. They didn't talk about current Kate, beyond the "She's doing better. She texted," at least she was texting her father, even if ignoring him. But they had become close. Him bemoaning Alexis reaching her last year of high-school and Jim enlightening him on all the ways he was lucky to have such a well behaved daughter with stories of teenage and child Katie. Boy had she downplayed her wild phase.

But Eduardo will hear from him. He liked the man. In the almost seven years he had lived in the building he had always been kind to them. Rick had been a little overwhelmed after publishing "In a Hail of Bullets" and "A Rose for ever after" and suddenly going from bartender with two jobs just to scrape by and living off a friend's charity to being able to afford a luxury apartment for his family, and Eduardo had never looked down on them like some of the neighbors who whispered behind their backs, not believing the family didn't have any recollection of who they were prior to that day eight years ago. Or even some of the staff, who thought they brought down the building's class, with his loud mother, his tomboy sister and him, the single father. Well, boohoo for them, because Rick had vowed to only give his family the best he could afford, after waking up with only the clothes on his body. And he worked very hard for that. Those first years he was producing four or five books a year. When he met Kate, he had been a published writer for a scant four years and yet he had over 20 best sellers published. So he earned everything he had and he would not let anyone say any different.

Enough daydreaming or mind ranting, he needed to see who was interrupting his very important brooding because his Detective wouldn't call, his book was finished and his daughter seemed to have abandoned him for another man, Ashley and his girly name, and to think he helped him! He must have been out of his mind. Yes, someone had to have drugged him. Probably a prank from one of the boys.

He opened the door and stared at Will freaking Sorenson of the FBI accompanied by Doomsday Fallon from Homeland Security. Seriously! You have got to be kidding him!

"Please tell me there are no bombs," he sighed before he could sensor himself in front of Kate's square-jawed perfect ex. He noticed that was common in all her boyfriends. Pretty perfect. Maybe he should lay off the smorletts…nah, what other joy did he have in life? Boy was he depressed!

"Depends on your outlook. Metaphorically, this is quite the bomb," Fallon said, "May we come in Mr. Castle?"

"Sure," he shrugged and moved to make way for them. That was when he noticed Sorenson crouching to someone on his side who was out of sight. Probably behind the wall.

"Let's go. I can say a lot of things about Castle but even I have to agree that he is a good guy," and Rick didn't know if to choke because Sorenson complimented him or because of the boy who timidly followed him inside the apartment. He was short, six or seven, if you stretched. Had the most awful pair of glasses on and clothes that were clearly new. Just bought yesterday new. But that wasn't what glued his eyes to the boy. Or the fact that the boy looked like a miniature, skinny version of him. Yes, he noticed that thank you very much. No, what made him unable to look away were the boy's eyes. Eyes that haunted his dreams. A vivid green that looked at him desperately from behind flames. But that couldn't be because his boy would have been nine right? He wasn't sure, but he always estimated the baby's age at around one. And this boy didn't look nine. He looked younger and scared. Really scared. Not I'm crying scared, but I'm trying to pretend I'm not but I'm ready to bolt scared. He knew that look well from many times he felt that way in more than one occasion. Last time Fallon was here came to mind. But mostly, he knew that look from Kate. Funnily enough not from when she was in front of a bomb, or a serial killer, but in front of him. Reaching dangerously close to territories they are not allowed to reach.

He forgot his manners as Fallon and Sorenson apparently decided to take the lead and seat down on the couch with the boy in tow as he automatically sat down in one of the armchairs in front of them himself, his eyes never leaving the boy and not a sound coming out of his mouth.

"Your name is James Potter," Fallon said in his usual curt and to the point way.

"Uh," he said dumbly not really paying attention. Still staring at the boy who was staring back. Almost daring Rick to prove him right and hurt him. Because he realized that was what this boy expected. He was good at reading people and he was starting to have the awful sensation that maybe this boy wasn't six, he just looked six.

"Castle!" Fallon called louder and Rick jumped to attention. "Your name is James Alexander Potter, you are a British citizen."

"No, I'm American."

"No, you just sound American," Sorenson said and some part of Rick - that was not busy trying to figure out if there was a chance that this was his boy. His boy who wasn't dead. Could that be? - rebelled against having Sorenson know anything about him that he himself didn't, "Apparently, you don't just have a memory bind. A spell that is supposed to be used to help people learn proper pronunciation when learning a new language was used on your mother language to make you sound American. So you wouldn't go looking for answers in England."

"So you are saying I'm a British Wizard," he scoffed. "I know how to use the internet?" he pointed out. Because British Wizards were well known for being the bane of everyone else's existence by refusing to join the rest of the world in the twenty-first century. They still lived as if they were living 200 hundred years ago. Thought non-magicals beneath them and refused to learn how technology worked. Risking exposure by doing magic in front of cameras all the time. Every other day there was an article on the papers about how the International Confederation of Wizards had failed yet again to convince the British Wizards to work with the Non-magical government to prevent the population at large learning about them, like everyone else did.

That was a major debate around the world. Most of the world had realized that to keep magic a secret from the population at large they needed certain non-magicals to know about magic and they needed to act sooner. Most of the countries had managed to merge both societies, the magicals integrating with the non-magicals and thus making the magical part easier to hide, since they knew how to act around non-magicals and since the government, first responders, law enforcement and medical personnel were also in the know. Magical education also started sooner and was mixed with non-magical curriculum. As a matter of fact, several schools had both kinds of students having spells and wards that didn't let the non-magical students learn about the magical classes. This made understanding of the non-magical society much easier since from an early age Wizards and Witches went to school with non-magicals. Not the British and a very few other countries in Europe. While the British non-magical government was aware of magic and took measures to make sure the Statute of Secrecy was kept, thanks to the help of foreign governments and foreign wizards, the magical British thought they were all well-hidden, which they weren't. They separated themselves and thought that was enough. Thought the non-magicals didn't notice them. In short, they were a pain for everyone else because all this caused was a lot of magic being exposed to cameras in England. And the fact that London was one of the cities with the most CCTV coverage in the world just added to the fuel. Bad combination. But because of centuries old treaties signed by the British crown and the Magical government, until the British Wizarding government decided to cooperate there wasn't much they could do without breaching those contracts. There were very few loopholes.

"From what we could ascertain, apparently your mother, who is from a very traditional, very anti-non-magicals family, rebelled by giving you and your sister a non-magical education before Hogwarts and you kept your studies up even after. You have a degree from Oxford," Fallon explained.

"Really?" he preened a little even though he still thought he was being bulshitted. "Oxford. So you say my name is James Alexander Potter, Alexander, my middle name now," he said with a dubious tone.

"Makes sense," Sorenson said. "They bound your memories, not your character. I read somewhere that you chose the last name but let your mother choose the first names."

"We were virtual strangers," Rick hissed angrily. He hated having to talk about what happened. How scared they all had been. They knew - they somehow knew what they were to each other but they didn't remember. Didn't remember each other's name or how they knew each other. They had functional knowledge, he could recite Shakespeare but he couldn't tell you his birthday. "I thought that would make her feel better. More connected." He also wasn't going to give Sorenson the pleasure of knowing he had chosen Rodgers for Captain America. At a time they were so exposed, so in need of help, he felt the symbolism appropriate. A superhero. When Black Pawn said Richard Rodgers was too much alliteration he once again went for the symbolism. Castles were strong. Castles were fortresses to protect those inside. But Sorenson didn't need to know any of that.

"Makes sense she would choose the same name. According to our information, James was a family name," Fallon said.

"A Potter family name," Rick said and for the first time the name clicked. The British Wizarding community was small on account of them not wanting to mix with the non-magicals, which led to interfamily marriages and less children for each couple. Other communities were larger because a marriage with a non-magical was common seeing as neither one had to choose to leave their world. A small college had more students than the Wizarding Brits had citizens. So there wasn't much repeat of last names and for the first time Rick looked more closely at the boy's forehead and not his eyes. "Holy shit!" he cried shooting up. And then his fatherly instincts kicked in. "You didn't hear that! Don't repeat that!" he said straight to the boy. The boy who was looking at him with big green eyes and a lightening bolt shaped scar on his forehead. The boy who cracked the first grin since he got here at Rick's bumbling.

"Yep, he is. Harry James Potter also known as the Boy Who Lived," Sorenson nodded grimly.

"No, no, no," he shook his head vigorously. "That can't be. Everyone knows the Potters are dead. Everyone knows the story. The father died first trying to stop Voldemort, in the living room and then the mother was found dead by the crib. Killing curses both, and the girl, the nine-year-old - same age Alexis was -" he whispered, "she died from the blast. That, there are history books with that story!" he insisted. "He can't be the Boy Who Lived. He's my boy!" he said without filter, because he knew, he just knew.

"Yes, that was the official version. Given by Albus Dumbledore and Charlus Potter, who also conveniently managed to keep any pictures of the Potter parents and daughter out of the media. But we found out that that is not the case. They are the ones who bound your memories. They are the ones who dumped you over here after holding you captive for almost a week. According to Potter you refused to see reason."

"Reason?" he asked horrified. "What reason?"

"They wanted you to give Harry to them so they could properly beat him down and when the time came they could sacrifice him to end Voldemort," Fallon said with a straight face and Rick couldn't hold it. He ran to the kitchen sink and puked his guts out.

A/N: So, a first introduction. I know, I know, he changed his middle name to Edgar. But I like Alexander better (plus, an Alexander would be very important to Kate, (wink). Pretend his website did not have his middle name) and while I can see him having to add the Castle for publishing reasons I can't see him changing a name that was chosen by his mother in such an extreme situation.