In a secluded valley in Iceland, Gummi and Kiddi live side by side, tending to their sheep. Their ancestral sheep-stock is considered one of the country's best and the two brothers are repeatedly awarded for their prized rams who carry an ancient lineage. Although they share the land and a way of life, Gummi and Kiddi have not spoken to each other in four decades. When a lethal disease suddenly infects Kiddi's sheep, the entire valley comes under threat.