You write: "a pair of wild dementors which where still sticking with him." You mean "...which were still...."
Also, I think the nasty werewolf is called "Greyback" in the American editions, not "Grayback".
Congratulations on your new job, wherever it is. At least, I hope that the move is because you have found some nice position in a History department where you'll have a bit of time to work on your research. (The fact that you're moving in August is evidence supporting this hypothesis.)