For Want of a Nail

"When thinking about the whole affair later, much later, Harry remembered a phrase he had heard in his schooling before Hogwarts: For want of a nail, the kingdom was lost.Though, after the disaster occurred, he thought of a very slight adjustment.For want of a blister, the dinner party was lost.For want of a dinner party, Harry’s Second Year was lost.For want of Harry’s Second Year, Dudley was lost."Or: The Chamber of Secrets has been opened, and Dudley Dursley is at Hogwarts. What could possibly go wrong?_______________Magical Dudley Dursley, Redeemed Petunia Dursley (...kind of. She's got a long way to go.)Canon Divergence, starting at the top of Chamber of Secrets.