L'île aux trente cercueils

The story proceeds in 1917. Veronique d' Hergemont is a 35-year-old nurse at the military hospital of Besançon. She suddenly learns the assassination of her husband, the mysterious Count Vorski, whom she has not seen for fourteen years. Its research will also lead it on the track of her father and her son whom she believed dead in a shipwreck (themoviedb.org)