"Heart of Ice" is the fourteenth episode of the first season of American animated television series Batman: The Animated Series, first aired on September 7, 1992, written by Paul Dini, and directed by Bruce Timm. This episode features the first appearance in the series of Mr. Freeze. In the comics, Freeze first appeared in Batman #121 in February 1959, with this episode providing a complete overhaul of his character, going from laughing stock to tragic villain.[1] The episode also introduces Freeze's wife Nora Fries and his motivation to find a cure for her terminal illness, both of which were later carried over to the comic books. The episode begins a four-episode and one film story arc for Freeze that continues in "Deep Freeze", the feature film Batman & Mr. Freeze: SubZero, The New Batman Adventures episode "Cold Comfort" and is concluded in the Batman Beyond episode "Meltdown". "Heart of Ice" is one of the most acclaimed episodes of the series, and won a Daytime Emmy Award for Outstanding Writing in an Animated Program.[2]