Dora Smithy appeared to be a simple secretary, working for Commissioner Gordon. Sister of Nora Fries and sister-in-law of Victor Fries, Dora made it her mission to put an end to costumed villains that ran about Gotham City on a daily basis.
Dora and her sister Nora were inseparable until Nora met her future husband, Victor Fries. Though Dora was resentful towards Fries, she tried to be happy for the pair. However, when Nora became terminally ill, Dora felt that her sister should be allowed to die in peace. Victor, on the other hand, would not allow it. During his employer's attempted shutdown of Nora's stasis unit, he became drenched in chemicals that altered his biological state so that he was forced to wear an environmental suit that would sustain him in a constant cold state. Because of this, Fries became known as the criminal Mr. Freeze.
Meanwhile, Dora became enraged and wanted to put away all costumed villains for good. Despite Nora's recovery as a result of Fries' technology, Dora pursued her mission by becoming a secretary for the Police Commissioner of Gotham City, James Gordon. She settled in and became friendly with Barbara Gordon, the commissioner's daughter.
Dora then set her plans into motion. After looting the Special Crimes Dangerous Evidence Vault, she discovered a Polarity Ray. With the Polarity Ray, Dora made all men in Gotham City vanish. As chances had it, Catwoman attempted to loot the vault the same night. Detective Selma Reesedale went to investigate and found Catwoman there with the entire vault littered with evidence. Selma, being a transgender woman got caught in the beam's affects and vanished.
With the men gone and so more than 90% of the criminals gone, Dora's plan was taking shape. With the new Commissioner and Mayor, attention was diverted away from her. Her plan did not include the possibility that someone else might obtain Mr. Freeze's Polarity Ray. Harley Quinn and Poison Ivy broke into the vault and stole it, among other things. When confronted by Batgirl and Catwoman (who wanted to clear her name of the kidnapping charges), Harley Quinn reversed the polarity, bringing all the men back. When Dora saw the Commissioner had returned, she immediately kidnapped him and replaced him with an android.
The android was programmed to authorize hunting down of all costumed criminals. With the change in the commissioner, the lack of sympathy for any life, Batgirl, as Barbara Gordon, confronted the android and destroyed it by throwing Batarangs at it, tipping it into the Bat-signal. Dora had taken Gordon to Gotham Ice Cream Industries where she kept him in a cryogenic chamber. Batgirl had figured her location with Detective Montoya. Montoya broke in but Dora, using Freeze's own technology, froze her inside of her car. Batgirl came in after and subdued Dora briefly. She managed to break free (unaware that doing so would open Gordon's chamber and revive him). With her enhanced strength, due to Freeze's gauntlets, she fought Batgirl and held her, with her desires of the costumed villains destroyed poured out.
Gordon was revived and told her that if it wasn't for Freeze then Nora would be dead by now. Dora refused to believe this. When told she was just like Mr. Freeze, just in a different costume, she denied it. She backed up on the catwalk she was standing on and fell into a bath of chemicals, similar to that her brother-in-law was exposed to years prior.
Dora was locked up in Arkham, under "cold storage".
Abilities and equipment
Dora's equipment was based largely on the technology of Mr. Freeze: cold effects, strength enhancing suits, and the like. Unlike Freeze, Dora did not require the suit to survive in normal temperatures. However, after the unfortunate chemical bath at the ice cream factory, she was rendered incapable of living in a normal temperature range and was left almost as immortal as Freeze himself.
Outside of her equipment, Dora had no known metahuman capabilities.
- It is apparently believed by some fans that somehow Dora later became the Killer Frost seen on Justice League Unlimited. This is mainly due to her being left in an icy state, both women having similar hairstyles and facial features and both having Jennifer Hale as their voice actress. However, there are no official statements to confirm or deny this.