The fields at Raven Fen yield barely enough for Agne and his family to live on, and his young son Klas can only watch as despair consumes his father. While Klas dreams of migrating birds - of escape - Agne imagines his crops devoured by insects never seen in Sweden, predicts endless cycles of storm and drought, hears only the ceaseless crowing of the ravens - and obsesses over the day when his son will take on his burden of toil.

But it is Sweden, it is the 1970s, and Klas can't accept the life his father has chosen for him. Caught between loyalty to his father and fear of his apparent destiny, Klas takes solace in nature, with the cuckoos, curlews and lapwings, far from the tormented world of Raven Fen. And as his father, like his father before him, falls deeper into madness, Klas begins to wonder if he himself might be insane.