The majority of Supergirl Season 5 has followed Lena Luthor secretly orchestrating an epic betrayal of her estranged best friend Kara Danvers. Now, this plan comes to fruition in a new promo for the Arrowverse series.

The DCTV series has released a promo from Season 5's eighth episode, titled "The Wrath of Rama-Khan," as Supergirl and the DEO deal with the immediate fallout from Lena's betrayal in the previous episode. As Kara flies above the Earth, Lena arms Kryptonite cannons to destroy her once and for all.

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"We have to stop her, the safety of the world depends on it," Alex Danvers implored her sister to confront their former friend as she launches her plans.

After killing her older brother Lex in the Season 4 finale, the dying villain taunted his sister with the reveal that her friend Kara had been keeping her superhero secret identity from her all along. Feeling betrayed, Lena quietly plotted revenge and a plan to remove free will across the globe to prevent anyone from ever betraying each other ever again.

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