Osiris was a great ruler of Egypt.
Along with his wife, Isis, Osiris ruled the country wisely, and
was well liked by his subjects. However, Osiris's brother, Seth,
was jealous of his popularity, and was plotting Osiris's murder.
One day, Seth secretly obtained the measurements for Osiris's
casket. Seth then had a beautiful casket made, and threw a large
feast for which Osiris and numerous others were invited.
At this feast, Seth produced the casket, and announced that whoever could fit inside it could keep it. Many guests attempted to fit inside the casket, but failed. Osiris then attempted the challenge. Once Osiris was in the casket, Seth immediately slammed the lid on the casket and sealed it. He then had the casket thrown into the Nile.
At hearing of her husband's death, Isis was devastated. She searched throughout Egypt and around the world for Osiris's casket. After years of searching, Isis found the casket at the roots of a giant tree. Isis then brought the casket back to Egypt for an appropriate burial.
Isis hid the casket in some marshes of the Nile for safekeeping before the burial. Unluckily for Isis, Seth found the casket in the marshes while he was hunting. Infuriated, Seth hacked Osiris's body into bits and scattered them throughout Egypt.
Isis then had to start another search throughout Egypt to find all of Osiris's parts. Eventually, Isis found all parts of Osiris except for one. She then put Osiris's body back together with bandages. Being the goddess of magic and medicine, Isis breathed life back into Osiris for one day. It was during this day that Osiris and Isis conceived their son, Horus.
Later, young Horus learned of his father's death. He then set out to battle his Uncle Seth to avenge Osiris's death. However, after several battles, neither Horus nor Seth was able to claim victory. In the end, Osiris became king of the underworld, Horus became king of the living, and Seth became king of the deserts as the god of chaos and evil.