Blake Lively will star in the movie adaptation of the best-selling romance novel It Ends With Us..
She'll act alongside Justin Baldoni, who is also directing the film..
Alex Saks and Christy Hall are the script writers..
Blake Lively is expected to play redheaded florist Lily Bloom..
Justin Baldoni is expected to play doctor Ryle Kincaid..
The actor playing Lily's first love Atlas has not been revealed..
This isn't Blake's first time bringing a complicated book character to life..
She recently starred as Emily in A Simple Favor based on the Darcey Bell novel.