DC Animated Universe
Nora's origin is in the episode "Heart of Ice", where she only appears as a cameo. In backstory revealed in the episode, Nora was married to Victor Fries, a GothCorp cryogenics researcher, but was diagnosed with a terminal illness. Victor resorts to cryogenically freezing Nora until he can devise a cure. However, GothCorp CEO Ferris Boyle, seeing the project as a waste of money, attempts to personally shut down Nora's life support; the resulting struggle exposes Victor to chemicals that render him unable to survive outside subzero temperatures. Designing a suit and weaponry, Victor swears to avenge Nora and would have murdered Boyle had Batman not intervened.
While she was left as presumed dead in "Heart of Ice", later events would bring her back. In the film Batman & Mr. Freeze: SubZero, Victor is shown to have transferred Nora to a remote cave in the Arctic. A submarine crew accidentally damages her chamber. Victor murders the crew before bribing an old colleague into helping him kidnap Barbara Gordon so he can extract her organ via an Allograft procedure (it is unspecified which organ, but is hinted to be a vital one in which the donor will not live, presumably the heart) to keep Nora alive. Batman intervenes and rescues Gordon, and Nora is eventually cured by Dr. Lyle Johnston of Wayne Enterprises.
In The New Batman Adventures episode "Cold Comfort", Nora is said to have waited for the presumed dead Victor for some time before eventually marrying her doctor Francis D'Anjou. This subplot is expanded upon in volume two of The Batman Adventures tie-in comic series, in which D'Anjou stages his abduction and death to frame Victor and make Nora hate him. After D'Anjou is defeated and arrested by Nightwing, Nora reunites with Victor in the Arctic Circle, revealing she never truly loved D'Anjou, but their reunion is cut short when Victor is seemingly killed fighting Batman after his head falls into the ocean. After talking to the incarcerated D'Anjou and Victor's adoptive Inuit son Koonak, Nora returns to the Arctic Circle to find her husband's remains. In the sequel comic series Batman: The Adventures Continue, Nora dies after her terminal illness returns.
Comic books
Freeze helps Nyssa al Ghul by creating a machine for the Society that can also be used to capture Batgirl. In return, Nyssa has offered to help him restore his wife using the Lazarus Pit. Though Nyssa has told him the pit needs to be adjusted for Nora, Batgirl convinces Freeze that Nyssa has no intention of reviving her at all, and he throws Nora into the pit himself.[1][2]
Because of all the years of being altered and broken, Nora absorbs the pit's alchemy, acquiring the powers to conjure flame and reanimate the dead. She becomes a supervillainess, calling herself Lazara. Mr. Freeze manages to stop her by freezing her once again.[3]
In The New 52 continuity reboot, Nora is not romantically involved with Victor, but is instead a young woman who, because of a terminal heart condition, was cryogenically preserved in the 1940s by Wayne Enterprises. In his attempts to cure her condition, Victor becomes obsessed with her. After Bruce Wayne terminates his research, Victor confronts him and is transformed into Mr. Freeze after inadvertently shattering a cryonic tank.[4]
In DC Rebirth, Nora's history is retconned to be similar to her original depiction. She was the wife of Victor Fries (having a career as a talented ballerina) but discovered she had incurable cancer. She had wanted to live the last years of the life of her own free will, but her husband forced her into the cryogenic storage.
In Year of the Villain, Victor revives Nora with a vial Lex Luthor gives him; in the process, Nora also develops her husband's altered physiology and receives copies of his suit and weapons to become Mrs. Freeze. She eventually abandons Victor after becoming infatuated with supervillainy.[5]
