Poseidon conceals his divinity as the mortal Semonus and marries Helena in search of his missing brother. She deems him worthless, betrays him, and divorces him on their anniversary for Orphneros—a false god. Poseidon sheds his disguise, devastates Helena, and unmasks Orphneros as the fraud who deceived Zeus. The true brothers unite, the impostor falls, and Poseidon finally finds peace with Amphitrite.
