Knowing the Galactic Empire was on the verge of collapse, psycho-historian Hari Seldon created two Foundations, one official, the other secret, which manipulate the evolution of Humanity. In 498, after their establishment, lightning suddenly threatened. Someone is distorting the cards of the game. Is it the Second Foundation, which the First believed to have eliminated, is it a third force, which works in the shadows and of which no one knows anything? Then begins a chase at the end of which hides a major surprise... Fourth part of a fresco of incomparable magnitude in the field of science fiction.