He grinned broadly at them and headed off to the staff table, still swinging the polecat.

"Wonder what he's been getting ready?" said Ron, a note of anxiety in his voice.

The hall was starting to empty as people headed off toward their first lesson. Ron checked his course schedule.

"We'd better go, look, Divination's at the top of North Tower. It'll take us ten minutes to get there. ..."

They finished their breakfasts hastily, said good-bye to Fred and George, and walked back through the hall. As they passed the Slytherin table, Malfoy did yet another impression of a fainting fit. The shouts of laughter followed Harry into the entrance hall.

The journey through the castle to North Tower was a long one. Two years at Hogwarts hadn't taught them everything about the castle, and they had never been inside North Tower before.

"There's — got — to — be — a — shortcut," Ron panted as they climbed their seventh long staircase and emerged on an unfamiliar landing, where there was nothing but a large painting of a bare stretch of grass hanging on the stone wall. Amelia had long since turned into a bluejay and was gliding along beside them looking rather bored.

"I think it's this way," said Hermione, peering down the empty passage to the right.

"Can't be," said Ron. "That's south, look, you can see a bit of the lake out of the window ..."

Harry was watching the painting. A fat, dapple-gray pony had just ambled onto the grass and was grazing nonchalantly. Harry was used to the subjects of Hogwarts paintings moving around and leaving their frames to visit one another, but he always enjoyed watching it. A moment later, a short, squat knight in a suit of armor clanked into the picture after his pony. By the look of the grass stains on his metal knees, he had just fallen off.

"Aha!" he yelled, seeing Harry, Ron, Hermione, and Amelia(who had turned back to normal to watch the painting).