In a sultry summer afternoon, the seasonal workmen, mainly from Africa, are harvesting wheat and stubble.
Antonio, from the garden of this country?house, is watching them with an entomologist eye. Then, in his library, he lingers over the different aspects of biological evolution.
In the big house everyone feels lonely. The wife is wandering from room to room driven by the memory of some verses recalling the spell of dawning love.
The younger daughter, moved by the first emotions of an adolescent, is running in the woods like a nymph, followed by young centaurs riding their steel colts.
Grandfather lying invalid in his large bed, suffers the immobility of old age, while the aunt is wandering around looking for a mysterious lost love.
All of them feel lonely and unquiet wrapped in the melancholy of the music played at the piano by the elder daughter.
Only for the young Africans there is a moment of full vitality while they are dancing on the banks of the river, after their work.
At last for Antonio, for the inhabitants of the house, for the workers, the animals, the trees and the river itself, for all of them, the evening comes down and the night.