James Jr. was a messed up kid, surprise, surprise. He was one of those kids who watched horror movies, and critiques the serial killer's methods. Next thing you know he's strangling cats in a back alley. So now that we know that little bit of flavor, back to the present, Alysia happens to be watching the movie seen in the flashback, when Babs returns back to the apartment for the first time in days, and though Alysia talks up a game, scolding Babs for freaking her out, she welcomes her back home with a big hug.
Both Babs and Alysia sit down, as Babs begins to open up to her roommate about everything, well, almost everything, the Batgirl stuff wasn't touched, but she goes through everything from the Joker to her brother. Alysia has a secret too, which you may have read around the web today, she's transgender! Not quite sure as to which she identifies as compared to what she actually physically has got going, but regardless... surprise! I think? I don't know, I guess I sort of saw that one coming? This is Gail Simone, who has been teasing this for a while.
Anyways, Babs eventually gets the call from her brother, and heads out with Alysia's blessing. Jr. isn't done making a few calls though, as he also calls his father, because it's a regular family reunion.
Babs' mother meets Jr. at the old aquarium first, and because he's a jerk, he pulls out a gun to welcome his mother. Babs isn't far behind, putting herself in between her mother and brother. Jr asks their mother if she knew that Babs was Batgirl, as if to shock her or something, but Barbara reveals that Babs already told her, and that SURPRISE! She's got a gun too, and shoots her sun in the arm.
Jr. crawls off, but Babs follows the trail of blood into a trap, in the form of a giant mallet to the back of the head. Babs begins to black out, but fights through the injury to go toe to toe with her brother, easily beating the crap out of him. Then, for some reason, Barbara Sr. gets close to her son to ask why he wants to destroy the family, which boils down to "Marsha! Marsha! Marsha!" as he grabs his mother, putting a knife to her mother's throat.
Babs is done, she decides to end the game, and in a quick sequence of events, she throws a batarang that hits Jr. in the eye, sends him flying back, cracks his back on the railing, then falls off the boardwalk onto a bunch of jagged rocks below, dead... apparently. Babs tried to save her brother, as she sits next to her mother apologizing, but things get worse, as James Sr. arrives, gun drawn, wanting to arrest Batgirl for murder.
With the weight of her actions already taking a heavy toll on her, Babs for a second contemplates a concussive batarang to get away, but opts not to turn on her father, and gets away while he fires shots at her.