This night on the CW the shows had a Lewis Carroll 'Alice In Wonderland' theme with the Supergirl (2015) and Batwoman (2019) episodes each named for one of the Alice books: Supergirl with Alex in Wonderland (2020) and Batwoman with Through the Looking-Glass (2020).
Kate refers back to her encounter with the Batman of Earth-99 as she wonders if she's heading down the same path that he did.
First appearance of Arkham Asylum since the Elseworlds crossover.
Camrus Johnson doesn't think Luke "would be really happy about it" if he learned what happened to August Cartwright. "Batman had a code for a reason, and Luke looks up to Batman. He trusts Batman's rules, and he knows that if Batman succeeded for this long and stood by these rules, then everyone should," Luke Fox's portrayer tells EW. That being said, "Luke knows some things about Bruce that Kate doesn't, and vice-versa, so I think Luke might be surprisingly forgiving, but at the same time, I don't think he would be too forgiving too quickly," he adds. "I think it would take a little bit more time before he forgives her because murder is no small deal." Johnson also suspects that killing Cartwright isn't the only issue Luke would have with this situation. "At the same time, I think Luke wants Kate to trust in him as much as possible and to tell him everything. So, I think it would hurt less knowing about this thing that she did, and I think it would hurt him more that she hasn't told him," he says. As showrunner Caroline Dries told EW last week, if and when Kate decides to tell people is part of the journey Kate is on following this massive transgression. "Part of dealing with the consequences of this will be how Kate decides to tell, or not tell, the closest people in her life. That decision will give insight into how awful Kate feels about this," said Dries.
The title refers to the sequel to "Alice's Adventures in Wonderland", which is called "Through the Looking Glass and What Alice Found There".