We takes place in a distant future, where humans are forced to submit their wills to the requirements of the state, under the rule of the all-powerful Benefactor, and dreams are regarded as a sign of mental illness. In a city of straight lines, protected by green walls and a glass dome, a spaceship is being built in order to spearhead the conquest of new planets. Its chief engineer, a man called D-503, keeps a journal of his life and activities: to his mathematical mind everything seems to make sense and proceed as it should, until a chance encounter with a woman threatens to shatter the very foundations of the world he lives in.