The address in the top left hand corner, which had led him to a corresponding flat in Halifax, was wholly unfamiliar. In the instant after he struck the knocker, Harry paused, gripped with a sudden fear. Perhaps he shouldn't have come, even to just thank Dudley and maybe even Petunia in person. What if Vernon answered the door? In their last in-person meeting, Harry's cousin and aunt had suggested to him that Vernon didn't know they were in contact, so would he, Harry, be getting them in trouble...?