The Illusions(2009)

Original title: Des illusions

A popular young writer decides to write a novel on an island that was once a Mecca to the Hippie movement of the 1960s. As he tries to recapture a world that no longer exists, the writer meets an enigmatic young woman who agrees to help him in his research. But as he falls in love with this strange girl, he finds her increasingly remote and mysterious, until she finally seems to disappear for good...