As Fletcher looks up at the night sky, the stars flicker out, one by one. Soon, instead of a starry sparkle, there is... nothing! Cynan sets out to help the stars shine again, but as he and his new friend the badger race through the winter woods, they find it's not easy to reach the stars... and help can come from unexpected places.

Wrth i Cynan edrych ar awyr y nos, mae'r sêr yn diflannu fesul un – ac mae ei ffrind newydd, y mochyn daear, yn ofn tywyllwch! Mae gan Cynan gynllun er mwyn achub y sêr, ond sylweddola'r ddau wrth rasio drwy'rgoedwig rynllyd, nad yw'n hawdd cyrraedd y sêr ... a bod help i'w gael o'r llefydd mwyaf annisgwyl.