Book: Theodore Nott and Voldemort
Who: Theodore Nott, Voldemort Where: Wherever they are When: December 29 Rating/Warnings: Summary: Voldemort books Theo.
After modifying the memories of Charlotte's killer and ensuring the man's physical condition -- including a deep gash on his arm -- matched the man's new memories, an exhausted Voldemort wrote Theo.
Mr. Nott,
I have made arrangements so you may take your revenge on your daughter's murderer. I'm sure, given your love of information, that you can appreciate how I'd know who the person was: I like to know who is casting the Killing Curse.
If you follow these instructions, you will find a house in a remote part of the English countryside. Inside you will find your daughter's killer. The house is protected by the fidelius charm; you will not be disturbed. The man will keep for several days.
Further directions to the house (along with the passing of the Secret) are written here.