Batwoman is a new player in town. She doesn't do things the way Batman does, and he's concerned with her lack of concern with human life. But their paths keep crossing. He's trying to find out what Rupert Thorne (a crime boss), the Penguin, and Carlton Duquesne are planning. Batwoman already seems to know. She's always there before him, destroying the operation (and the evidence, unfortunately).
He manages to follow her once. She goes to a penthouse owned by Duquesne. Bruce Wayne follows his daughter the next day, and gets caught up in her escape from her protector goons. He's quite taken by her. The things Kathy says, her anger at her father for her mother's death, make him think she's the Batwoman.
He questions that idea later. While on a date with her at the Penguin's Club, Batwoman breaks up the gathering. She's after Penguin and sues some very hi-tech gadgets. Bruce sees Kathy and Batwoman at the same time.
When Batman analyzes the gadgetry, he realizes it's the same composition as one of his worker's new inventions. When he goes to question Dr. Rocky Ballantine, she uses martial arts on him. He warns her to watch out. But he realizes she can't be Batwoman either. She was at Wayne Enterprises when Batwoman was taking something else down.
Batman is working with Sonia, Detective Bullock's partner. He has her track down some things. She admits to him he saved her life once. After Rupert Thorne's men burnt down her parent's shop, he pulled her out of the fire.
Which one of the three women is Batwoman, or are any of them? Will Batman find out in time to save her from Bane?