I love your story - the ideas in the prologue were so good - Dudley's kids being 'afflicted' with magic was something I had wondered about myself (pity that Granny Petunia's still being such an arse about this sort of thing, though sadly it's pretty much in keeping with her), and you developing this by sending David Dursley to Hogwarts to meet ghostly Snape is just a genuis plot-line! (Sorry if I'm being over-effusive but this is the most impressive fan-fic I've read in ages). I can't wait to read the next chapters so I'll leave this here - thank you so much for posting this!

I can't not comment on David being a 'hopeless Hufflepuff' - again, great move.