Berlin, Christmas, the dead of night: 16-year-old Alissa and her best friend, Evelin, are making their annual secret pilgrimage to the grave of Alissa's father when Alissa falls through thick snow to land in an underground crypt. There she finds a child's casket... with a strange black plant growing up through its lid. Opening the coffin, she severs the dark growth from its roots--and discovers they are embedded in the heart of the dead child.