Attack at Hogwarts
The Dark Lord had given them the job to find the way to Hogwarts. Them! The Werewolves. They hadn't disappointed him. It had taken some time and they had found the entrance from the Hogsmeade Station. There were no guards, nothing preventing them from going inside.
As a reward, the Dark Lord sent them first with the Dementors along, two Dark species working together, moving under the castle and then moving up until they were getting up again, moving up stairs.
Finally they were out from the tunnels and inside Hogwarts. Soon they would have control of the castle.