Elixir by Hilary Duff yes, Hilary Duff aka Lizzie Maguire. Don't let that put you off this intriguing paranormal young adult mystery. Clea is the daughter of a well-known scientist and a politician and has been in the spotlight her whole life. An interest in photography has turned into a career for her and allows her to travel all over the world.
After her father goes misssing while on a humanitarian mission, Clea notices a strange figure that appears in all of her photographs. Could it have something to do with her father's disappearance? As Clea begins to search in earnest for clues to her father's disappearance by searching his office and lab clues emerge that indicate the possibility of past lives and unforseen connections that lead to a current love triangle.
The story has an incomplete ending which leads one to believe that this installment is just the first in a series. Either way, be sure to enjoy Elixir by Hilary Duff.