Abused by the Dursley's and ignored by everyone else, Parseltongue becomes Harriet Potter's escape and brings out her Slytherin side. After a chance encounter with Draco aged 8 brings her abilities to light, Lucius takes an interest and inducts Harry into the magical world. Fem!Harry, Super!Harry, Slytherin!Harry. Not M for a long time but might get dark later.
AU. Pettigrew returns to Voldemort far sooner than expected and so Voldemort is ready for his reincarnation ritual when Harry is only 8 years old. Still unaware of magic, Harry runs away from his the abusive Dursley's only to find himself face to face with Voldemort. Severus comes to his aid, and the two are forced to help each other through the darkest of times.
Harry Potter was born into magic and then removed from that world for ten whole years. This is what happened during his life with the Dursley's. (Slight AU - warning physical abuse by Dursley's.)