Warning: The following contains SPOILERS for Batwoman, season 1, episode 11, "An Un-Birthday Present."
The latest episode of Batwoman introduced a doppelganger of Beth Kane from another Earth elsewhere in the Arrowverse; one where Beth Kane lived a normal life and never became the crazed killer known as Alice.
The conflict between Kate Kane and her twin sister has been one of the linchpins of the Batwoman series. Kate's efforts to redeem Alice were born of her own feelings of guilt and her fears that maybe she might have saved Beth from the car crash that delivered her into the hands of the madman whose abuse transformed her into Alice if she'd been a little bit better and a little bit braver as a child. Those feelings became stronger after Alice confirmed that Kate and her father had come very close to rescuing her after her abduction but that they gave up too soon in confronting the man who was holding her captive.
The latest episode of Batwoman, "An Un-Birthday Present," opened with Kate Kane celebrating her birthday and returning to her office to find a doppelganger of Beth Kane waiting for her. Assuming this was another of Alice's tricks, Kate attacked Beth only to send her twin screaming. Thankfully, Beth left behind her purse, which gave Kate all the evidence she needed to determine that somehow, whether it was because of her birthday wish to get her sister back or a side-effect of Crisis on Infinite Earths, a sane version of her sister was now living on Earth-Prime.
In Beth's World, Kate Saved Her From The Car Crash
The most notable difference between Beth and Kate's worlds was also the most heart-breaking, as it confirmed Kate Kane's worst fear; that there was a chance that she might have saved her sister from the car accident that sent her falling off a bridge, washed downriver, and discovered by the mad Dr. August Cartwright. The proof lay in the fact that, in another world under what were seemingly the exact same circumstances, she did save her sister.
According to Beth, her Kate climbed back into their car as it was teetering over the edge of a broken bridge and helped pull her to safety. On Earth-Prime, Kate merely called to her sister and encouraged her to try and get out of the car on her own while trying to weigh the back of the car down and keep it from slipping further. Thankfully, Kate found some degree of personal redemption by the end of the episode. Kate was able to save Beth from a fiery death, after Beth became locked in the trunk of a car that had been set on fire by the Wonderland Gang, mirroring the rescue attempt she never made as a child.
Beth And Kate Are Best Friends, Even As Adults
After their first violent encounter, Kate was able to track the doppelganger Beth down because she went to the same park the two had always gone to on their birthday as girls. After talking her twin down, Kate discovered that, as when they were young, the Kate Kane of the alternate Beth's Earth was her best friend as an adult. The two were close, even by the standards of twin sisters, as evidenced by a photo of the two together on Beth's phone; one which Kate recognized as being identical to the picture of the Kate Kane and Beth Kane of Earth-99, which Supergirl had given her during Crisis on Infinite Earths.
Related: Biggest Arrowverse Questions After Crisis on Infinite Earths' Ending
Beth Has A Master's Degree In Astrophysics
As the two sisters caught up, Beth revealed a bit about her background, chiefly regarding her education. She held a Master's Degree in Astrophysics and had just returned to Gotham City from a semester of studying abroad while working on her doctorate. To her horror, what had been her apartment on her Earth was a boys dormitory on Earth-Prime and nobody at the science department of her college recognized her now.
Despite all these shocks, Beth acclimated to the idea that she'd somehow been transported to a parallel Earth quite well once Kate explained about the Crisis. The concept of multiple universes was one that she was familiar with from her studies. She was also quick to find the bright side of nobody knowing who she was on Earth-Prime apart from Kate, quipping that "none of my exes know me here either."
Kate Kane Had No Tattoos On Beth's Earth
The one thing that Beth found most astonishing about Earth-Prime was Kate Kane's trademark tattoos. As the two sisters were comparing notes about their respective worlds, Beth asked what each of the tattoos meant and how she was able to have them without being disowned by their father. Presumably the Jacob Kane of Beth's Earth (who was still commander of Crows Security) was less permissive than the Jacob Kane of Earth-Prime, having never gone through the tragic loss of one daughter and becoming more flexible regarding the rebellious behavior of the other.
Kate's Bar Is Beth's Bank
One of the odder notes that Beth makes regarding the differences between their respective parts of the Arrowverse is that the bar Kate Kane is in the middle of establishing in an abandoned building in Gotham City is still a bank on her Earth. The point came up after Kate took Beth to her bar to share a drink as the two got to know each other. Beth looked around the place and told Kate that the weirdest aspect of her dimension-hopping was how normal everything felt and how "despite your tats and the fact that this used to be my bank...it feels like I'm back on my Earth and it's just a normal day just chatting to my sister." It remains to be seen if Beth will become a normal part of Batwoman's reality, but her arrival has given Kate Kane a newfound sense of hope that was sorely needed coming out of Crisis on Infinite Earths.