Susan approached the Hat rather more sedately than the first girl had, and sat down calmly, and donned the Hat, and thought, Excuse me, but do you know why people are so against cross-House friendships? The thing was, her parents had been from two different Houses (the House of Bones had been Hufflepuff for ages, but her mum had been a Ravenclaw), and she was just so very curious how it'd happened. The House separations were getting worse, her Auntie had said, and she really wanted to know if she could fix that ...