Everything starts somewhere, although many physicists disagree.
...is the beginning of Terry Pratchett's Hogfather.
I'm not sure I think that's an especially engaging opening--it's the whole opening paragraph, not just the opening sentence--but I'm not sure I think openings are Terry Pratchett's strength. The Hogfather is the Santa Claus-like figure of Terry Pratchett's Discworld universe, though that's Death taking his place on Hogswatch Eve on the cover of my edition. It seems the Assassin's Guild has something to do with that.
Book Beginnings on Fridays is a bookish meme hosted by Gilion at Rose City Reader. To play, quote the beginning of the book you're currently reading, give the author and title, and any thoughts if you like. Happy Hogswatch to all!