Following their adventures in Yr Horwth and Melltith yn y Mynydd, the heroes of Copa Coch venture from their home for the first time, trailing the mystery that hides in the hills and marshes of the kingdom of Bryn Hir. -- Cyngor Llyfrau Cymru Publisher: Atebol Cyfyngedig Author(s): Elidir Jones Number of pages: 304 Publication date: 2022 Dimensions: 130 x 185 x 28 Cover type: Paperback / softback Illustrator: Huw Aaron