Tellemicus Note: I got inspired for this story after playing the unbelieveable game of 'Assassin's Creed III' and reading a number of AC fanfics and crossovers. Also, a shout-out to Andor Swiftblade for helping me refine some of the ideas in this story. Sadly, I haven't been able to figure out where to go after where I left off, I'll have to leave that up to whoever chooses to do this story.
And finally, my proposed pairing is due entirely to the fact that I'm a shameless Harry/Fleur lover. Feel free to change it as you desire.
Harry Potter and the Assassin's Creed
A Medallion and a Scepter
Assassin's Creed:
Stay your blade from the flesh of an innocent.
Hide in plain sight.
Never compromise the brotherhood.
Voldemort was captured by the Templars of Abstergo Industries as he was exploring the magical ruins of the Holy Land in search of a fabled artifact of immense power. Abstergo stole the artifact (the Scepter of Eden) and tortured Voldemort in search of answers to his identity and how he found the Eden Piece they'd spent centuries looking for. Once he was finally able to escape (five years later), Voldemort's hatred of Muggles was at its peak and he became determined to exterminate them as soon as possible. He was able to steal the Scepter of Eden back before he fled Abstergo.
Back in England, he discovered that the Scepter was capable of bestowing him with tremendous charisma and swaying the people to his beliefs. Voldemort used the Serpent to great effect during the early days of his hostile takeover attempt of the Wizarding World prior his downfall to Harry on Halloween. Once he gained a substantial following of underlings, he hid the scepter in the Room of Hidden Things, along with his diadem Horcrux.
When Harry (7) was at the playground, he bore witness to a savage battle between an Assassin and group of Templars. Enthralled despite the danger, Harry tried to help the Assassin by throwing rocks at the Templars, distracting them momentarily, enough for the Assassin to strike them down. Afterwards, the Assassin thanks Harry and hurries off to finish his mission.
The Assassin returns several days later to speak with the boy. He finds Harry trying to mimic his fighting style and sees the boy's natural talent quite clearly. Further interested, the Assassin speaks with Harry, learning of his home life and realizing the boy's a wizard. The Assassin offers to teach Harry to become a defender of the weak and to fight for liberty and peace for all life. It was an offer Harry was all-too-willing to accept.
Taking Harry home, the Assassin spoke with Vernon and Petunia, offering them a considerable bribe to take Harry as his ward. It wasn't until they refused that the Assassin felt the compulsion wards surrounding the home, telling him that someone powerful wanted to keep Harry here. Carefully fracturing the wards with one of his few magical items, the Assassin repeated his offer and it was quickly taken. The Assassin immediately had Harry completely undress and redress in new clothes (not even letting him keep his glasses) and then they quickly leave. It wasn't until after dinnertime that Hagrid came barging in, expecting to find a warzone and Harry badly hurt or killed.
Over the next few years, Harry gets trained to become an Assassin and to fight the Templars. Harry's first mission was given to him by his Master as a request from a wizard. Nicholas Flamel's Philosopher Stone had been stolen from his bank vault by Dumbledore under the guise of protecting it at Hogwarts. Dumbledore's plan had been to use it as bait to draw out Voldemort, to see if Voldemort still existed in the world. Harry's mission was to infiltrate the school, find the Stone before anyone else was able to steal it, and return it to Flamel. Harry was even able to switch the Stone with a perfect fake which, once Dumbledore discovered it was, led the old man to believe that the Stone had been stolen or the one Hagrid had taken from Gringotts had been fake along.
In early 1995, it was discovered by the Assassin Order that a renegade Templar had stolen a Piece of Eden before disappearing 60 years earlier. Unable to pass up the chance of recovering another Piece, the Assassins get to work on locating this mystery Templar. During his sleep, Harry receives visions of something being hidden away in Hogwarts, something magical and extremely powerful. Feeling compelled to discover this item, Harry once again sneaks into Hogwarts to find the mysterious disappearing room and what was hidden.
However, by a stroke of bad luck and fate, Harry was discovered by a group of snobby Purebloods and captured by Snape. When the intruder was brought before him and his identity revealed, Dumbledore was dumbstruck to realize that it was Harry Potter. Dumbledore immediately tried to read him to learn where he had disappeared to but found that he was unable to. Harry's mind was far too trained in the mind arts and was mostly successful at evading Dumbledore's attempts.
Learning through talking with him, Dumbledore learns that Harry was unwilling to return to the Magical World and reclaim his place within it. With no other means of swaying him, Dumbledore uses his own Piece of Eden on Harry (much to Harry's tremendous shock). Dumbledore's Eden Piece is a medallion worn around his neck. It is a capable of locking away a person's original personality, creating a new replacement one, and implant false memories to suit the role Dumbledore wants the victim to play. He wants Harry to be a martyr. Dumbledore is able to introduce Harry as a transfer student who was joining the public education system after several years of homeschooling because he wanted to meet and interact with people his own age.
When news of the Boy-Who-Lived's 'miraculous return' reached his Assassin Master, the man was furious at both Harry for going to Hogwarts without consulting him and at Dumbledore for publicizing it. He sneaks into Hogwarts and is able to corner Harry, quickly discovering what Dumbledore had done to him. Using his own brand of mind magic, the Assassin was able to mostly restore Harry's memory and true personality. Finally sharing the details of his impromptu mission with his Master, the Assassin agrees with Harry's idea of staying at Hogwarts. It would allow him a chance to fully explore the castle in search of that hidden room and the mysterious item within, and potentially steal Dumbledore's Medallion. The Assassin leaves, giving Harry an emergency Portkey to escape Hogwarts should Dumbledore ever try mess with his memories again.
During his explorations, Harry unintentionally draws the attentions of a certain maiden who develops a strong interest in him and his 'clearly' hidden agenda. She knew he had one since, as a Veela, she could sense deception from those around her. Sneaking into Hogwarts one night, Fleur goes in search of Harry to figure out what he's hiding and why. Even though he tried to lose her and continue his search for the disappearing room, Fleur was still able to keep up with him by following her instincts and his faint scent. He finally confronted her on the seventh floor, trying to scare her into leaving. All he ended up doing was increasing her curiosity for him.
Hearing the approach of a Prefect (attracted by the scuffle they made), they frantically search for a place to hide, causing a door to magically appear near them. Comparing the door to his dream-vision, Harry realizes that he's finally found the room. After the coast is clear, Fleur demands answers from Harry, and he grudgingly submitted because he owed her a debt of gratitude for helping him unintentionally find the room. Fleur knows that he didn't tell her the whole truth, only what he felt was safest for her to know. This caused her curiosity to only deepen as she realized that he was part of something truly big, a conspiracy that he wasn't willing to expose to the world.
Leaving the room, Fleur waits in the hall as Harry goes back into the room to find that which he was looking for. After 40 minutes, he emerges with a strange scepter in his hand. He swears Fleur to absolute secrecy about what she'd seen him find because, if the wrong people learned of it, bad things would happen to good people. As the little misadventure began to end, Fleur discreetly hinted to Harry that she was going to eventually discover the truth of what he was up to, that she'd have her eye on him. The next day Harry sent a letter to his Master about the successful recovery of the Piece. Now all that's left is the Medallion.
Shortly after the end of the Triwizard Tournament but not the school year, Harry was contacted by his Master. He and five other Assassins were going to enter Hogwarts and steal the Medallion, from Dumbledore's corpse if needed. Harry was to play the role of a student until the Assassins arrival. Then, win or lose, Harry would depart with his Master after the mission was ended.
On the day of the scheduled infiltration, Harry dresses in his Assassin whites, marches straight into the Great Hall during mealtime, and bluntly demands Dumbledore hand over the Medallion. When Dumbledore refuses, claiming it was a family heirloom, Harry calls his lie when he declares that he'd stolen it from its rightful owner and had been using it to manipulate the students for dozens of Hogwarts generations. When the teachers try to retaliate to the slander, they find themselves suddenly attacked and immobilized by undetected intruders, sending the students into a panic. Harry again repeats his demand for the Medallion in exchange for he and his accomplishes not massacring the students (a well-concealed but entirely-possible bluff). Dumbledore tries to trick Harry by giving him a fake Medallion with a Portkey charm on it, but Harry dodges it and snatches the Medallion from Dumbledore's robes, fleeing by triggering his own Portkey (along with the other Assassins).
The 'attack' becomes a highly publicized and controversial event thanks to Skeeter's exaggerated articles on it, along with Harry Potter's sudden and unexplained disappearance following the attack. Dumbledore realizes that somehow his attempt at regaining his figurehead and martyr had been foiled by those mysterious white cloaked men and he is able to manipulate the Ministry into issuing search and arrest warrants for another wearing a white cloak. Voldemort hears about the white cloaked intruders and vaguely remembers something from his past about them, something to do with ancient magical artifacts. Fearing that he may have lost his secret power, Voldemort sends Peter Pettigrew into Hogwarts to find and retrieve the scepter, only for the rat to report that the scepter was missing from where Voldemort claimed to have hidden it. After the school year ends, Fleur decides to relocate to Britain so that she can find Harry and finally get the full story out of him.
The Assassins prepare for a confrontation with the Ministry because they know that Dumbledore will use all of his power to find them and recover 'his' Medallion.