The narrative unfolds in the sleepy Austrian village of Eseldorf during the late sixteenth century, a community deeply insulated by tradition, religious devotion, and rural isolation. Three young boys, Theodor Fischer, Nikolaus Bauman, and Seppi Wohlmeyer, spend their days roaming the woods and the park of a rarely visited princely castle. Their lives are upended by the appearance of a charming, graceful youth who calls himself Satan and claims to be an angel. Possessing miraculous powers, he casually creates living clay figures, summons food out of thin air, and manipulates time and space with absolute indifference to human suffering.
Satan’s presence brings both wonder and devastation. He performs seemingly benevolent acts, such as providing unexpected wealth to the disgraced priest Father Peter to save him from ruin, yet he destroys innocent lives with chilling nonchalance, arguing that mortals are of little consequence. As the village struggles with the inexplicable wealth, suspicions of witchcraft arise, fueled by the local astrologer. The community turns on Father Peter, plunging him and his niece Marget into renewed despair. The boys bear the heavy burden of knowing the truth about the gold while being forced into silence by Satan's invisible protection.
The tension in Eseldorf escalates as the witch-craze tightens its grip on the superstitious inhabitants. Satan continues his visits, treating human ambitions, wars, and moral righteousness with scornful amusement. He demonstrates the deterministic nature of human existence, showing how the smallest acts irrevocably shape future tragedies. Despite the boys' affection for him, his cruel disregard for human life and his cynical perspective on the moral sense leave them deeply disturbed. He maintains that humanity is governed by fear, hypocrisy, and the tyranny of aggressive minorities rather than reason or true kindness.
Tragedy strikes the boys directly when Satan alters the life-path of Nikolaus, leading to his premature drowning alongside the child Lisa. Although Satan insists that this intervention spares both from prolonged agony and degradation, the loss shatters the remaining innocence of Theodor and Seppi. Meanwhile, Father Peter loses his sanity from the shock of his trial's chaotic aftermath, retreating into the permanent delusion that he is a powerful emperor. Through these events, the narrative paints a bleak yet darkly humorous portrait of human society, driven by self-deception and illusions.
In the concluding phase, Satan takes Theodor on sweeping, instantaneous journeys across the globe and through human history, exposing the endless cycles of bloodshed, oppression, and hollow civilization driven by the moral sense. He dismisses human pride in warfare and progress as mere childish absurdity. Finally, before departing forever, Satan shatters Theodor's entire perception of reality with a staggering revelation. He declares that the universe, God, humanity, and the earth have no objective existence, but are merely the empty, wandering thoughts of Theodor alone in shoreless space.
