The Ghost Rider - Who brought Doruntine?

An old woman is awoken in the dead of night by knocks at her front door. The woman opens it to find her daughter, Doruntine, standing there alone in the darkness. She has been brought home from a distant land by a mysterious rider she claims is her brother Konstandin. But unbeknownst to her, Konstandin has been dead for years. What follows is chain of events which plunges a medieval village into fear and mistrust. Who is the ghost rider?