SPOILER WARNING: This article contains major spoilers for "The Bottle Episode," the midseason premiere of Supergirl.


Right on the heels of "Crisis on Infinite Earths," Supergirl had to deal with the Anti-Life Equation.

In "The Bottle episode," the midseason premiere, Kara and her friends encountered several different Brainy doppelgangers. Each had arrived on Earth-Prime through a dimensional wormhole at Al's Bar. When they attempted to resume their normal routines, they discovered each other -- and the fact that their Earths are dead. Soon, they realized someone was killing them off one-by-one, using a very particular weapon: the Anti-Life Equation.

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"He seems to have been killed by some sort of biosynthetic virus," Alex mused.

"The Anti-Life Equation," Brainy's female doppelganger supplied.

"It's a techno-organic poison," another explained.

"It's targeted and transmitted through the Big Brain," the female Brainy added.

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As it turned out, one of the Brainys present had bottled his Earth in an attempt to save it from "Crisis'" antimatter wave. He wanted to free his people, but -- if he did so -- he would destroy both worlds. When his doppelganger attempted to stop him, he unleashed the Anti-Life Equation, killing him.

In the comics, of course, the Anti-Life Equation is Darkseid's endgame. As conceived by Jack Kirby, the Anti-Life Equation would allow the New God to erase the free will of any sentient race. It is tied to the Martians, whose philosophy was based on the Life Equation. As such, it makes sense for the Anti-Life Equation to surface on Supergirl, which has dealt with Martians frequently thanks to main character J'onn J'onnz.

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The Anti-Life Equation was not brought up again in the episode, and Darkseid was never directly mentioned. As such, it likely won't lead to the appearance of any New Gods on the Arrowverse series, but it was a notable reference to the larger DC Universe.

Airing Sundays at 9 p.m. ET/PT on The CW, Supergirl stars Melissa Benoist as Kara Danvers, David Harewood as Martian Manhunter and Chyler Leigh as Alex Danvers.

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