How does Santa know who has been naughty and who has been nice? From the elf on the shelf, of course! This book and 'elf' gift set has become a popular holiday tradition for families with young children. Meet author Carol Aebersold, co-author of The Elf on the Shelf: A Christmas Tradition. Carol will sign and read from The Elf on The Shelf, and talk about this magical Christmas phenomenon. It's not required, but please rsvp if possible to 781-721-5933 or email@example.com.