Good Friends

This is a Fanfiction in the fantastical world of Harry Potter. The story is centered around Luke, a Pureblood who is determined to be in Gryffindor. He thinks being in any other house, especially Slytherin, would bring him shame. His parents were in Gryffindor, and so was the rest of his ancestors. So he is determined to also be Gryffindor.
He meets three other people on the train to Hogwarts. One is a sassy blonde named Noelle, another is a quiet brown-headed kid named John, and the last was a dark-headed girl named Samantha who barely spoke. John had invited him to the compartment. When Noelle asks what house he'd like, he says, quite loudly, that he'd be in Gryffindor. They then engage in an argument about the houses all the way to Hogwarts.
He, like he'd hoped, got sorted into Gryffindor. John was sorted to Hufflepuff, Samantha to Ravenclaw, and Noelle to Slytherin. Despite the different houses, they become fast friends. But Hogwarts is colder than they thought. What are the teachers nervous about? And why can't Luke shake the feeling it has something to do with the founders of the school?