A note from Will Sawyer was laid across on Matilda's pillow (much like what his father did), courtesy of the family owl. This is the message that was enclosed:
Matilda,
To be blunt, shit has happened around here. Fucking shit. I don't feel comfortable about writing it in a letter, so I'd like to talk about it in person. In a couple days, I'll be moving out into my sister Sophia's flat in Diagon Alley. The building's address she lives in is 23 Main Street, and her building is 2A on the ground floor. You can't miss it.
Hopefully I'll see you in a couple days.
-Will.