When she came in it sure looked like it was writing in ink with its tail but now it's definitely not doing that; the parchment's blank. The tail's still inky.

She goes and writes a letter and gives it to Amber.

He is back a little while later soaking wet and having handed out six detentions. "Swan. Have a moment?"

"I'm not busy."

"I'm going to go change into something dry, can you come up in ten minutes?"

"Okay."

He changes into something dry.

She comes up in ten minutes.

He's wearing fluffy slippers. "Thank you for telling me. I don't know how long she would have been all right."

"I need a pass for flying my broom in the corridor, I think Twimble saw me."

"I'll write it up." He doesn't move. "Did you have a question for me?"

"I'm not sure if I should have a question for you."

"If I were going to tamper with your memory I'd have done it immediately. Also I'd never do it to anybody but I expect that to be less compelling as a reassurance."

"I'm an Occlumens. That doesn't mean I should definitely have a question for you."

"Well, let me know." He pulls out some parchment and starts writing a letter for Twimble. 

"What were you doing with the mouse."

"I was practicing the Imperius Curse."

"Why do you know the Imperius Curse."

"With practice people can learn to throw it off."

"Why were you practicing casting the Imperius Curse."

"So I can someday teach the people who'll need it how to throw it off."

"Don't you have to hate them or something."

"You can't mean well. I don't know the exact parameters on that but I intend to find out."

"How'd you learn it."

"No comment."