"God Emperor of Dune" is the fourth novel in the Dune series by Frank Herbert. Set thousands of years after the events of the previous books, it follows the story of Leto II Atreides, the son of Paul Atreides, who has transformed into a hybrid of human and sandworm. Leto II rules the universe as a tyrant, believing that his oppressive reign is necessary to ensure humanity's survival. The novel explores themes of power, sacrifice, and the nature of leadership. Leto II's unique perspective on time and his vision for the future drive the narrative, as he grapples with the consequences of his choices and the burden of his god-like status.