Half Light (2006)

Rachel Carlson is a successful mystery novelist whose life falls apart when her five-year-old son drowns at her country home. A year later, in an effort to heal her wounds and help her to start writing again, her best friend rents her a secluded cottage in a remote fishing village, where events unfold that rock the tranquil village and cause Rachel to fear for her sanity and her life.

Official website: http://www.half-lightmovie.com/