"That one!" he called to the others. "That big one — there — no, there — with bright blue wings — the feathers are all crumpled on one side."

Ron went speeding in the direction that Harry was pointing, crashed into the ceiling, and nearly fell off his broom.

"We've got to close in on it!" Harry called, not taking his eyes off the key with the damaged wing. "Ron, you come at it from above — Hermione, stay below and stop it from going down and I'll try and catch it. Right, NOW!"

Ron dived, Hermione rocketed upward, the key dodged them both, and Harry streaked after it; it sped toward the wall, Harry leaned forward and with a nasty, crunching noise, pinned it against the stone with one hand. Ron and Hermione's cheers echoed around the high chamber.

They landed quickly, and Harry ran to the door, the key struggling in his hand. He rammed it into the lock and turned — it worked. The moment the lock had clicked open, the key took flight again, looking very battered now that it had been caught twice.

"Ready?" Harry asked the other two, his hand on the door handle. They nodded. He pulled the door open.