Crisis On Infinite Earths: Why Did Kate Keep the Kryptonite?

This article contains Crisis on Infinite Earths spoilers.

The Batwoman episode of The CW’s epic, five-part crossover event saw Kate Kane teaming up with Kara, aka Supergirl, to travel to Earth-99 in search of one of the Paragons who could save the multiverse from the machinations of the Anti-Monitor.

Once there, Kate meets that world’s Bruce Wayne (played by Batman: The Animated Series‘ Kevin Conroy), an older man who has turned hateful and bitter after a lifetime of vigilantism. While Kate initially believes this version of her cousin could be the Paragon of Courage they are looking for, it quickly becomes clear that he is not. 

“This is Bruce Wayne after giving and giving and giving and giving of himself his entire life to try and heal the world, and never getting anything back personally that replenished that well,” Conroy told us in an interview. “It’s what happens if Bruce never finds love. And the Bruce I had always played was one who was always toying with finding love. Whether it was Andrea Beaumont, or Selina Kyle, or various people. But this is what happens if he’s never ever gotten anything to replenish his soul. I’d never played that.”

“Part Two” is a reminder for us viewers of how the people we think of as heroes can be turned against us under the right circumstances. For Earth-99’s Bruce, it may be a lifetime of isolation and loneliness, but for Earth-96’s Superman, it is Lex’s harnessing of the Book of Destiny and, for our Oliver Queen, it is the repercussions of the Lazarus Pit. In this context, it’s not so hard to understand why Kate might be wary of her fellow heroes, given their immense power…

read more: Every DC and Arrowverse Easter Egg in Crisis on Infinite Earths Part 3

In the episode’s final moments, we see Kate check on the hidden Kryptonite she snagged from Bruce’s exoskeleton, hinting at the possibility of her using it against Kara. In “Part Three,” we almost immediately see the tease come to fruition. When Kara goes to use the Book of Destiny to try to bring her world back, Kate threatens to stop her—using whatever means necessary, including her Kryptonite.

They are able to work out their differences with words rather than fisticuffs, with Kara realizing that the Book of Destiny is not the answer to her problems. However, when Kate goes to give Kara the Kryptonite, the Kryptonian tells her to keep it—a symbol of how much she trusts Kate’s judgment, and also an acknowledgment of the reality that even Kara can be corrupted and is too powerful not to have a contingency plan for.

This is a cool callback to the comics, in which there is a longstanding tradition to have Superman willingly give Batman a chunk of Kryptonite because Bruce is the person he trusts most to stop him should he lose control. 

If the Kryptonite doesn’t pop up again in “Crisis,” there’s always future crossovers to consider. Batwoman and Supergirl will no doubt be part of the Arrowverse for a long time to come, and, with Arrow on its way out, Kate is set to become one of the central trifecta alongside Supergirl and The Flash. The Kryptonite could show up down the road, if it doesn’t rear its ugly head before this Crisis is over. Let’s just hope that visit to Earth-99 wasn’t foreshadowing for Kara and Kate’s future relationship…

Kayti Burt is a staff editor covering books, TV, movies, and fan culture at Den of Geek. Read more of her work here or follow her on Twitter @kaytiburt.