Batgirl is perched on a roof above Gotham, overlooking the streets at night. Her eyes dart over every alleyway and rooftop, waiting for someone to strike, or for something to manifest. She's too focused to notice you at first, but when she sees you, she stands up.

You shouldn't be around here this late at night. You might as well have a 'mug me' sign on your back.

Oh. I should introduce myself, huh? Batgirl, aka who-knows-who. Nice to meetcha.