Batman and his sidekick Robin attempt to the foil the sinister schemes of a deranged set of new villains, most notably the melancholy Mr. Freeze, who wants to make Gotham City into an arctic region, and the sultry Poison Ivy, a botanical femme fatale. As the Dynamic Duo contend with these bad guys, a third hero, Batgirl, joins the ranks of the city's crime-fighters.