Cyfres Genod Gwyrdd: Achub Afon!

The second fantastic book in the series about four friends who want to make the world a better place. Izzy and Poppy are being taking their boisterous dog, Billy, for a walk when he lands in the river. It is so choked with rubbish that Billy can't get out. A brilliant series about the small changes that make a big difference, with themes of environmentalism and friendship.