Unhinged

Matteo Flammel (Riddle). He just showed up...out of nowhere. We know that he was Voldemort's long-lost son, that he didn't know Matteo had been rescued from that heinous place. He's grown up under the care of the one and only, Nicolas Flammel, who had saved him from the orphanage and from the same fate as his brother. He was too young to know the truth. Dumbledore knows he exists, but he doesn't know that Matteo is actually Tom Jr's brother and Voldemort's son. And Nicolas is adamant that Dumbledore never finds out. But what happens when he suddenly shows up at Hogwarts? What happens when he figures out that he's actually a Riddle? What will Dumbledore do when he finds out Matteo's real name?

What if Harry Potter had a sister...a twin to be exact? Why had he not known about her? She didn't have the same scar, and no one knew she existed...or was it all a lie made up by Dumbledore in order to protect the other Potter? Did Dumbledore even know she existed? If not, how did she get out of the Potter's home before Voldemort got there? Does she know her true heritage? How will she react to meeting Harry? Who raised her? When the wizarding schools of Durmstrang and Beauxbatons come for the Triwizard Tournament, the Potter twins will finally meet.

Will Matteo be as bad as his father? Will Y/n Potter be like her brother? How will the new additions affect the school? We'll see all of this and more in "Unhinged", a love story if you can believe it. This will be a rewrite of the Goblet of Fire, with a few of my own twists and turns.
The idea to write a Matteo and reader fanfic is simple: Matteo is consistently mentioned, but never talked about, and I'm tired of it. Some say he's Voldemorts' son, others say he's his brother, but I'm going with son; as well as separating out Tom Riddle Jr. from Tom Riddle Sr., for the plot of course

*JK Rowling owns these characters, except for my additions and the characters I've created.* Book 1 of 4