July 31st is regular day, nothing special about it. Except for a few select people of course. Especially for Harry and Hermione, during their summer of their 4th year. Why? Because they get their creature inheritance. They find out many things about their family, their heritage, their powers, and the wizarding world. Most importantly, they find out they are the Riddle Twins.
Both Harry and Voldemort get something they were deprived of growing up.
She was called a mudblood and said she would be nothing. (She was going to change the world) He was always in his brother's shadow, they'd already done it all. (He was going to make a name for himself) He was stuck with expectations and notions of what he should be. (He was going to become someone thought to be a myth) The Sorceress, The Tempest, The Hero
Harry had known he was different since he was little. And he hated it; he wanted to be normal. Being different came with too much pain for him. All he wants, is to meet someone who accepts him, maybe even is just like him! And he does! But even then, there are expectations that have been set in front of him. Watching, he knows he needs to change things. So he starts planning.