Toss Another One on the Pile

Well, shit.

While Agamemnon is away, Aegisthus usurps the throne of Mycenae. When Agamemnon returns, Aegisthus invites him to a feast, whereupon he murders Agamemnon. Years later, Agamemnon's son Orestes returns and kills Aegisthus and Clytemnestra, but the Furies prevent him from taking the throne. Athena holds a trial in which the role of each parent in procreation is central and rules in favor of Orestes, who becomes king of Mycenae.

Compare to:

While Osiris is away, Set makes plans to usurp the throne of Egypt. When Osiris returns, Set invites him to a feast, whereupon he murders Osiris and usurps the throne. Years later, Osiris's son Horus defeats Set and kills Isis, but Set prevents him from taking the throne. The gods hold a trial in which the role of each parent in procreation is central and, on the advice of Thoth, rule in favor of Horus, who becomes king of Egypt.