On Batwoman Season 1 Episode 15, Kate and Jacob have a chat with August Cartwright about his mom. Meanwhile, Alice finds Mouse but things go very, very wrong from there.
On the day of their bat mitzvah, Gabby Kane gave her daughters their necklaces which matched her earrings.
In the present day, Alice leaves August Cartwright bound next to the Bat Signal for Batwoman to find.
At the Cartwright farm fifteen years ago, Mabel Cartwright moves in with August, Mouse, and Alice. She is cruel and abusive to Alice, jealous of the girl's youth and beauty.
Kate calls Jacob and explains about Cartwright and how Alice is still alive. Cartwright tells them about Mabel's treatment of Alice.
Alice finds Mouse and unbinds him from the Fear Toxin. Suddenly, he turns on her and knocks her out and binds her to the chair and puts the Fear Toxin mask on her. She relives all the horrors of her life with Mabel as well as imagining Jacob and Kate both turning their backs on her.
Mary and Luke get a lead on the car Beth's killer drove. They find it in a junkyard and find the gun in the trunk. Luke runs the plates while Mary tries to find a way into the Batcave. They connect the dots to Mabel Cartwright.
Jacob rescues Alice before she can commit suicide but then she shares the final horror of the ordeal with Mabel. August had found and kept Gabby Kane's head when he found Beth. He froze it, planning on transplanting Gabby's face onto his mother's. He gave Mabel Gabby's earrings and after Alice finds the head, she kills Mabel by burning her alive with her oxygen tank as a blowtorch.
When August tells Kate about his plans with Gabby's head, she loses control and kills him.
On Batwoman Season 1 Episode 15, August shares a dark story of Alice's childhood with Kate. Mary & Luke track Beth's killer. Alice and Jacob have some quality time alone.