Dinah and Barbara in “Premiere”

You've been here before, haven't you?

It was a long time ago. Another life. Before I was ever Oracle, I had another name, another identity. Another self. I used to work with a man, Helena's father. He was Gotham's greatest champion, and most people never even knew he existed. The last time I ever fought at his side was in this place. We'd cornered the worst criminal Gotham had ever known, smashed his organization and hunted him down. I know Batman could have killed the Joker but he didn't. And his honor had a price. The Joker got away from the police, only for a few hours, just long enough to send a man to kill Helena's mother and to come for me himself.

Why?

I think the Joker wanted to drive Batman mad. And maybe he did a little. Because a few months later, he left. Left New Gotham, his work... Everything. Even the daughter he never knew he had.