"And see this?" said Sirius, pointing into the cabinet. "This lock of hair belonged to our sister."
"We don't have a sister," Regulus frowned.
"We used to. She died. You're probably too young to remember."
"You're lying."
"I'm not. She lived in your bedroom. She fell out of the window and went splat on the ground. Her brains squirted out everywhere, Kreacher had to clean it up."
"He didn't!"
"He did. And you know that clanking noise at night?"
"The pipes —"
"No. Her ghost. She's coming for you, Reg, she'll haunt you forever because you took her bedroom."
"She won't!"