Disclaimer: All content you can recognise is not mine
Note: In this story Hogwarts is a sixth form only school, so magical kids learn normal "muggle" stuff like Maths and English (or similar magical-culture influenced versions of those) till they're 16, then go to Hogwarts to learn magic for two years.
Chapter 1:
The Dursleys never wanted anything to do with the Potters, that's why when they found baby Harry Potter on their doorstep, they immediately left him at the local Orphanage with a short note saying: "That's Harry, please take care of him." Thankfully, the gifted child was adopted by a young middle class couple, Adrian and Lucy Whitfield. They were both lawyers and had a nice house in suburban London. They were a loving couple and raised Harry lovingly and happily.
It was a fine June evening at the Whitfield's. Harry Whitfield, 15, was studying in his room, the end of school was near, and he was looking forward to spending the summer with his friends. His parents were probably watching television or working on some case; they were both lawyers and often worked together. He then heard the front door open downstairs, and, after a slight delay, perked his head in surprise, all his family was at home, and no one else had the keys. All sorts of thoughts went through Harry's head, he was suddenly worried these were burglars, and feared for what they might do to his parents. Reacting just like a character from a really bad movie, he picked up the heaviest object in sight, in this case one of his old gymnastics trophies that was on a shelf, and slowly made his way downstairs, trying to make as little noise as possible. He crouched down and made his way towards the living room, from where footsteps could be heard. Readying himself, he opened the door, and finding himself in front of an unknown man dressed in black with an open bag in hand, Harry leapt and bashed the trophy as hard as he could on the man's head. And even though Harry was still small for his age and not all that strong, by some "miracle" he managed to completely knock out the presumed burglar, which promptly fell to the ground, unconscious. Harry, not stopping to realise what he had just accomplished, found his mom and dad in his line of sight. And, though bound to chairs with rope and having duct tape across their mouths rendering them speechless, they looked safe and unhurt. Still seeing a look of distress in his parents' eyes, he turned and saw there was a second man in black, who had his hands in a backpack putting something inside it or taking something out. Without giving the man the time to figure out what had just happened to his companion, Harry jumped on him to hit him on the head too, but only mid-jump did he notice the gun the man had just taken out of his backpack. Harry heard the gunshot, then the sickening sound of his trophy hitting the man's head, still with a force a 15 years old shouldn't have been able to gather, and finally a big pain in his lower stomach. Harry passed out as his head hit the floor.
A.N. : Just an idea I have had for a while, not originally written as a fanfic, but it blends well in the end, and there will still be magic and Hogwarts... Please tell me what you think about it!