Osiris did not return to the land of the living. Instead, he descended to the Duat—the Egyptian underworld—to become its eternal king. He traded the crown of the living for the Atef crown of the dead.
Osiris: Death and Afterlife of a God In the golden age of the First Time, Osiris reigned as the shepherd of Egypt. He was the "Lord of Perfect Justice," the one who taught humanity the arts of agriculture, the law of the land, and the secrets of the vine. But where there is light so pure, a shadow must fall. That shadow was his brother, Set—the god of storms, chaos, and the red desert. The Great Betrayal Osiris: Death and Afterlife of a God
Driven by a jagged envy, Set devised a plan of architectural cruelty. He crafted a magnificent chest, built precisely to Osiris’s proportions, and promised it to whoever could fit within it at a royal banquet. When Osiris lay down inside, Set’s conspirators slammed the lid, sealed it with molten lead, and hurled it into the Nile. Osiris did not return to the land of the living