Claim: In Secret was based on a book.

In Secret , previously titled Thérèse , is a 2013 American erotic thriller film written and directed by Charlie Stratton . Based on Émile Zola 's 1867 classic novel Thérèse Raquin , the film stars Elizabeth Olsen , Tom Felton , Oscar Isaac and Jessica Lange . It was screened in the Special Presentation section at the 2013 Toronto International Film Festival . The film received a regional release on February 21 , 2014 .