SUNDAY DECEMBER 1

Yule season did strange things to people. It had the power of transforming the most frumpy of individuals to a happy child, or the most tartan of teacher's offices to a kind of Santa's workshop for Scottish Folds.

Professor McGonagall was not as cheerful as the current state of her room. She was angry.

She could scream and threaten to quit her job, but Sirius just couldn't see how she expected anybody to pay attention when her office was full of squishy, grey cats with floppy ears.

"Answer me now," she said, angry. "Which one of you is the Gumball Wizard?"

For once in his life Sirius was innocent. He wasn't the Gumball Wizard. He had only spraypainted Gumball Wizard on the new pinball machine in the Chamber of Fun last night.

"It's not me," said James.

He wasn't the Gumball Wizard either, he had only wanted the brand new steel ball in the brand new pinball machine last night because he liked small balls. It wasn't James who had put a little gumball in its place, and thusly caused it to overheat and break down entirely while what looked like an alien life form from planet Pink devoured everything under the glass.

"Nobody," said Sirius. "Just thought it was funny."

"Funny?" said McGonagall, like she could not see it. "You thought it would be funny to put gum in a pinball machine and watch it break down?"

He hadn't thought it would be, but it had been partly because the pinball machine wasn't all that had suffered a breakdown.

"We didn't think that would happen," said Remus quietly and constantly on the verge of nodding off.

"You didn't think it would happen," said Sirius. "I didn't really think anything."

"I said it wouldn't work from the beginning," said James. "Of course you can't substitute steel with sugar!"

"Why would you even need to substitute the steel ball?" McGonagall asked.

"Er... It was to test a hypothesis. Can you play pinball with a gumball? Turns out you can't."

Professor McGonagall removed her square glasses and rubbed the lines under her eyes, like it was hard work for her to sit on her cat-warmed tartan cushion, choose a detention slot in her calendar and get free labour for a few nights.

"You have too much energy, that's the problem," she said. "We'll need a few chaps to shovel all the snow this winter. A few sessions a day should exhaust you sufficiently. I shall inform the caretaker that you can start right away."

Not Mr. Filth!