Ismene was a princess of Atlantis. Her mother, Queen Antinea of Atlantis, selected her for sacrifice, as its was prophecied that Atlantis would meet its doom if a daughter of Antinea outlived her. However, she was rescued from Uranus' son Proteus the Monster by Heracles, who brought her back to Atlantis. There, Antinea feigned remorse for her plan to sacrifice Ismene, holding a feast to honor Heracles' victory, while privately reminding Ismene of her intent to sacrifice her. Heracles later rescued Ismene from a ship that was to be set ablaze as a sacrificial pyre, and Heracles' destruction of the Stone of Uranus' protective cave led to the rays of the sun striking the stone and causing Atlantis to explode, killing Antinea and her followers as Ismene sailed off with the Greeks.