Celeste is a Frenchwoman who befriends Kia Clementine when they meet as tourists in Lake Como. She's married to Thomas Masterson and they had a daughter Clemence Masterson who died. She speaks English and Italian in addition to French.
- "Celeste was awesome, chatty, friendly all in this droll, sophisticated, cosmopolitan way that was way beyond cool." - Ashley, Kristen (2011-12-28). Heaven and Hell (Kindle Locations 919-920).
- "unusual eyes, eyes the like I’d never seen, a light brown with hints of blue, her perfect skin touched with sun but not brown, leathery and wrinkled, her dark hair that was worn casually in a stylish cut that suited her heart-shaped face" - Ashley, Kristen (2011-12-28). Heaven and Hell (Kindle Locations 1342-1344).