The Transfiguration teacher sat in his office, correcting some homework. There was a hard, solid-sounding knock at the door. "Enter," he said.
Aberforth stomped in, graceless as usual. He spoke without preamble and did not mince words. "Albus Percival Dumbledore," he began, pointing a finger at his brother, "you are a worthless coward."
"Abe, I did not invite you here. Please leave."
Aberforth did not seem to hear this. "You're a disgrace to our family. Our father would've been ashamed of you. Call yourself a Gryffindor? You're afraid to fight, you're afraid to do what it takes to save the innocent. You know you could beat him and no one else can, and yet you sit here in your school and do nothing."
"Get out of here!" said Albus, his temper rising. Few things mattered as much to him as his House or his family's honor, and Aberforth knew it. "You've no idea –"
"No idea?" roared Aberforth. "I've a better idea than you think, Albus! I know exactly what's going on. I've figured out more than you, even though people call me the slow one." He looked as though he had an unpleasant taste in his mouth. "I know what Grindelwald was to you."
He had never said the hated name before. It made the weight of his statement even more frightening. "I'm not blind, you know. I was there. I know everything, and I never told a soul. But now –"
Albus couldn't breathe.
"You need to go, Albus," said Aberforth, slowly. "You know what your duty is, and you've shirked it for too long. You're the best wizard anyone's ever seen. They say he's got the Deathstick, the wand no duelist can defeat. If anybody can stop him, it has to be you. Your feelings don't come into this. The war is what matters."
Still, Albus could say nothing. Finally he croaked, "Go."
Aberforth growled, "You'd better be packed and out of here by tomorrow, making yourself useful for once. Otherwise, you won't like what I'm going to do." He stomped out, with one last glare over his shoulder at his brother.
Albus sank into his chair, feeling as though the floor had fallen out from under him.