At the Spring Fashion Show, Donna Day of Donna Day Fashions presents her new fashion line. As the show progresses, a mysterious woman dressed in green with an attractive, feminine figure and dark hair, but wearing a featureless white mask, appears with three muscular male henchman. Disrupting the event with a smoke bomb, she and her henchman kidnap Donna Day and escape, leaving behind a calendar page. Later, in giving a statement to the press, Detective Harvey Bullock inadvertently dubs the new villainess "Calendar Girl."
Later that day, Bruce Wayne meets with Lucius Fox to discuss the new production specifications for Wayne Motors, and the auto show that Bruce Wayne is to attend later that night. On his way out, Lucius reminds Bruce about the upcoming retirement dinner for senior manager Bernie Benson. Bruce responds by saying he thought that the manager was younger and expresses surprise at the retirement. Lucius comments that "sooner or later we all start covering the gray" as he leaves the office.
That night, Bruce is being driven to the auto show by Alfred. Upon pulling up to the convention center, Alfred comments that some thoughtless person has parked a van right in front not giving him a place to park. Bruce immediately realizes something is wrong and orders Alfred to drop him off elsewhere so that he can change into Batman. Inside, the auto show continues as normal with Gotham Motors unveiling its new car: the Solstice, complete with a young model on the hood.
Calendar Girl soon appears with her henchman, this time dressed in yellow and wearing a red, white, and blue top hat. Batman appears and orders the villain to surrender and let go of the young model. Calendar Girl answers that she has no quarrel with the young girl, but the young girl is just another "unfortunate victim" and lets her go while releasing bursts of fireworks coming from her hands. She and her henchman escape with Barkley James, the head of Gotham Motors, leaving behind another calendar page. Back to her hideout, a disused nightclub called "Faces," both of the captured people try to make a deal for their freedom using their wealth. They are rebuffed and told to be quiet because the boss was thinking. Calendar Girl, in the meantime, was in the back of the club's darkened dressing room. She had her mask off and was surprised by one of her henchman who she lashes out at for trying to see her face. She puts her mask back on and goes out to announce that the next stage of the plan is about to begin.
Back at the Batcave, Batgirl has done research and found something in common between the two companies as well as the dates circled on the calendar pages left behind at the kidnappings. Page Monroe, a once famous spokeswoman and model used to have contracts with both Gotham Motors and Donna Day Fashions and the dates on the calendar pages were the dates when her contracts ran out.
Later, Batman and Batgirl pay a surprise visit to her former agent, Irv Kleinman. Batman intimidates the agent and gets the info he wants. After her modeling career dried up he got Page Monroe a part in a sitcom which was cancelled shortly after it began. He also says that after Page disappeared from view that there were rumors that she had been disfigured in an attempt to restore her to a more youthful appearance so she could continue working as a model.
Calendar Girl next appears at a party to celebrate the unveiling of the WGBS' new lineup of shows. All of these shows are youth oriented. As Calendar Girl is abducting network executive Frederick Fournier, Batman and Batgirl show up and chase the villainess into a backlot of the studio and consequently deal with a large remote controlled mechanical dinosaur. Batman destroys it by toppling a huge assembly of spotlights on it. The next day, Bruce is at his office when Bernie Benson enters to turn in his final report before getting ready for his retirement party. Their conversation is interrupted by a phone call from Batgirl who confirms after some research that Page Monroe holds title to a nightclub called "Faces." Bruce says that he will meet her there. He apologizes for not being able to attend the retirement party and says that he will change the retirement policy so that Bernie can keep his job for as long as he can do it.
At Calendar Girl's hideout, the three captives are shown pictures of Page Monroe in her prime and they're all told that there is only one more holiday to celebrate - the Day of the Dead. She appears, dressed in black and carrying a scythe. Batman and Batgirl arrive and a brief fight ensues were the slide projector showing pictures of Page Monroe is damaged and this causes her to be distracted and easily beaten.
Afterwards, as the police are leading everyone away, Bullock rips off Calendar Girl’s mask. She writhes around, trying to hide her face and screaming at everyone not to look at her. Above, Batgirl is stunned to see that Page is still a beautiful woman, her face virtually unchanged from her modeling days. Sadly, Batman remarks that Page can no longer see herself as anything but "flawed."