Sirius, I need you to set off at once. You are to alert Remus Lupin, Arabella Figg, Mundungus Fletcher —the old crowd. Lie low at Lupin's for a while, I will contact you there."
"But —" said Harry.
He wanted Sirius to stay. He did not want to say goodbye again so quickly,
"You'll see me very soon, Harry," said Sirius, turning to him. "I promise you. But I must do what I can, you understand, don't you?"
"Yeah," said Harry.. "Yeah... of course I do."
Sirius grasped his hand briefly, nodded to Dumbledore, transformed again into the black dog, and ran the length of the room to the door, whose handle he turned with a paw. Then he was gone.