Watch a report by ITV News Anglia's Natalie Gray
Downton Abbey star Catherine Steadman has written a psychological thriller set in one of the East of England's most famous beauty spots - Holkham beach in North Norfolk.
Catherine played the sassy Mabel Lane Fox, Lady Mary's rival in the hit ITV drama.
The book Mr Nobody is about a man who wakes up on an Holkham beach in winter, his memory gone.
Catherine, who grew up in the New Forest in Hampshire, discovered Holkham while on a film shoot in 2008 when she stayed overnight in nearby Wells-next-the Sea.
She's an actor famous for the small screen but her first book is already being adapted for the big screen.
Watch out for Reese Witherspoon's film company releasing Something in the Water soon.
So what is next for Catherine ? Writing or acting ?
Mr Nobody is out now in paperback.