A woman with supernatural healing abilities, Medea is encountered by Hercules, Iolaus, and Jason on their way to find and slay a Ghidra- A two-headed monster that has been terrorizing local villages. They first meet her at a lake when Iolaus and Jason attempt to spy on her and catch a glimpse of her bathing. After almost killing Iolaus, she ends up joining them on their journey. However, she is secretly working for Hera, who promised her power and freedom from an overly-controlling stepfather. Thus, she uses her feminine wiles to cause dissension between Hercules and Jason so they will be unable to defeat the Ghidra and Hercules will most-likely be killed in the attempt.
When she begins to develop genuine feelings for Hercules, though, Medea ends up going against Hera's wishes and admits to the plot. After the damage is undone and the monster destroyed, Hera takes her anger out on Medea and sends her away, presumably to be tortured or killed.