Harry sighed, frustrated because he didn't need the distraction from trying to find Ron. The trail was cold and he hadn't been back to his flat, though, so he decided he might as well go rather than brood. He didn't want to let his former Head of House down, and maybe she could even give him some new ideas to explore.
Calling over the waiting owl, Harry wrote a quick reply on the back of Professor McGonagall's note.