Iolaus is Herakles's close friend and nephew. When Herakles performed the Twelve Labors, Iolaus was by his side. When Herakles dies, Iolaus agrees to watch over his children; they desperately need this protection because of their enemy, the King of Argos. Iolaus is old but brave and is the one who gets the King of Athens to agree to protect the children.

Alcmene is the mother of Herakles. She wants King Eurystheus to be put to death once he's captured.

Macaria is one of the children of Herakles. When King Demophon refuses to sacrifice or demand the sacrifice of a girl from Athens, she agrees to be sacrificed to guarantee Athen's success in the battle.

Hyllus is the son of Herakles who challenges King Eurystheus to combat. The king refuses.

King Eurystheus of Argos wants the children of Herakles dead; he pitted himself against Herakles and fears the children of the man he wronged will eventually come after him.

King Demophon is the king of Athens. He agrees to help protect the children on the condition that they bind themselves to him and become his kin.

Copreus is the herald of Argos who says that Iolaus needs to take the children to Argos. Once there, they'll be stoned to death.