A child of Osiris and Isis will end the rule over man. Isis and Osiris were the gods and were worshiped by the humans. Osiris brother Seth god of the underworld was jealous of all the attention that his brother received. So he planned to murder his brother.
Seth created a beautiful coffin made to fit Osiris and said "Who ever can fit it can have it". Osiris laid in it and Seth shut and nail the coffin shut. He threw the coffin in the Neil river and it was lost to the river, Isis went searching for her husband but never found him. Their sun Horus swore to avenge his father by killing Seth.
As he prepared for battle his father Osiris visited his son in spirit and asked him what he was going to be in disguise. He replied "A horse because i can cut off any escape."
Seth and Horus meet up at a river to battle. Seth is disguised as a hippopotamus. Seth tried to sneak up on Horus but he saw it coming and the battle lasted for decades. Finally Horus slained Seth and avenged his father.
After decades of searching Isis finally found her husbands body. His body grew into a healthy tree. Before Horus snailed Seth the god found his brothers body and tore him into pieces. He threw his body parts across the earth.
After years Osiris's body parts started to grow into beautiful trees and plants. Isis saw that the plants started to overgrow and put animals on the land. Then she created human beings to keep the number of animals down.