There's a dungeon level!

"Great," sighs the fairy with the prisoners. He gets altitude so he can see into the dungeon without getting near the dementors and collects the last few humans. Then it's off to the moon.

And all the Dementors are boxed!

"Where do you want me to put you?" Treeleess asks.

"Near the place we left from, I'll wait there for you so Ister can make you the rest of your stuff..."

So, trailing many boxes of Dementor, she zooms them back toward Hogwarts.

Which is good timing because there are people flying towards where Azkaban used to be and it'd be mildly inconvenient if they recognized him.

She puts the boxes high up so they don't inconvenience random Scots, drops Timothy off, and zips into space.

He writes Cam a note. It says 'Azkaban dismantled, no one lost their wands'.

Cam may be presumed pleased about this.

Treeleess is back first, then her conspecific.

"Hey! Thanks so much. Ister can make the rest of your stuff now."

The fairies collect their stuff.

"Thanks again! Should I grab you again if I have more projects?"

"Honestly I just took a summons because I thought it might get me pants quicker than going home," says the unnamed fairy.

"Sure," says Treeleess.

Fairies can go home.

Bye fairies!

Ister can stop being a delightful instrument of Timothy's will.

"This is the best trip ever," comments Ister.

"I am really glad! I should get back to school before someone wonders if my disappearance is related to the dismantling of Azkaban. Have a nice day!"

"I will!"

He Apparates to the edge of the grounds and then walks in. 

Nobody troubles him particularly.

Back to Milliways, as he goes sending Michael a note telling him where to find them.

He meets him at the top of the stairs. "What's going on -"

Door closed - "lot of things. Most notably I just dismantled Azkaban and relocated all the prisoners to the Moon and I want to teach you how to summon demons."

"Ah huh." He looks around.