"SO WHAT?" Harry shouted. "Don't you understand? If Snape gets hold of the stone, Voldemort's coming back! Haven't you heard what it was like when he was trying to take over? There won't be any Hogwarts to get expelled from! He'll flatten it, or turn it into a school for the Dark Arts! Losing points doesn't matter anymore, can't you see? D'you think he'll leave you and your families alone if Gryffindor wins the house cup? If I get caught before I can get to the stone, well, I'll have to go back to the Dursleys and wait for Voldemort to find me there, it's only dying a bit later than I would have, because I'm never going over to the Dark Side! I'm going through that trapdoor tonight and nothing you two say is going to stop me! Voldemort killed my parents, remember?"
(Harry Potter and the Sorcerer's Stone)
Based on the reading, the key elements of melodrama present in this quote are black or dark being evil, an underdog hero with determination but not necessarily talent, exaggerated emotions, and a strong dichotomy between good and evil. Harry refers to Voldemort and his followers as the dark side, and their practice as the dark arts. He knows what the correct thing is in this dangerous situation, and resolves to do it, despite being woefully unprepared and unqualified. He has the hard-luck past of losing his parents and being adopted by semi-abusive relatives to spur him on. He screams at his friends in an effort to make them understand the dire situation, although his explanation of the possible fallout from his intended actions range from death, which is undoubtedly the worst outcome, to being forced back to his cousins' house, which seems foolishly mild in comparison. Lastly, he draws a clear line between good and evil, dark and light, us and them. Gryffindor, home of the heroes, is contrasted starkly with Voldemort and the Dursleys, the epitome of evil in Harry's opinion.
"And?" Harry replied. "Maybe you just don't get it. If somebody else beats us to the stone, Voldemort will be back. It was much less fun to be at Hogwarts when he was here. In fact, we might not even be able to go here. He might get rid of it entirely. It doesn't really serve much purpose for him. Our in-house competition is significantly less important than this problem. They are actually entirely unrelated concerns. If I don't get to the stone first, I'll go back to my cousins' house and wait things out. I'm going to go after the stone and you guys can come if you want, but you shouldn't try to stop me from going just because you don't want to come. This means a lot to me."