A genetic engineering experiment gone horribly awry turns a large flock of docile sheep into unrelenting killing machines in this rural horror comedy directed by Jonathan King and featuring special effects designed by Weta Workshop. When the death of his father and a stress-induced fear of sheep pushes him toward the edge of a nervous breakdown, skilled farmer Henry Oldfield leaves the family farm behind in a desperate bid to achieve inner peace. Upon returning to the farm following a 15-year absence, Henry discovers that his brother Angus has been performing genetic experiments on the sheep. Unfortunately for both the brothers and the rest of the humble farmers who make their living off of the land, these experiments have produced a strain of sheep that crave human flesh and will stop at nothing to satisfy their diabolical hunger.