Warning: SPOILERS for Supergirl season 3, episode 11 'Fort Rozz' ahead
In this week's episode of Supergirl, titled 'Fort Rozz', the Girl of Steel faces off against Reign – but someone else is killed by the Worldkiller. Season 3 of Supergirl has explored the internal struggle of Kara (Melissa Benoist), whose Kryptonian identity as a member of the House of El is sometimes at odds with her human upbringing in the Danvers family. Another character struggling with their identity this season is Samantha Arias (Odette Annable), who is living a double life as the Worldkiller known as Reign - but Samantha has no knowledge she's suiting up as the superpowered villain terrorizing the criminals of National City.
In the latest episode of Supergirl, Kara leads a team to the defunct Kryptonian prison Fort Rozz while looking for Jindah Kol Rozz (Sarah Douglas) in order to learn more about Reign. Unfortunately, Fort Rozz is now orbiting a blue star, which means Kara won't have her powers, and the star additionally poisons anyone with a Y chromosome - meaning J'onn J'onzz (David Harewood) and Mon-El (Chris Wood) can't accompany the Girl of Steel. So, Kara assembles a team of female allies to help her track down Jindah: Imra Ardeen (Amy Jackson), Psi (Yael Grobglas), and Livewire (Britt Morgan). However, not everyone makes it back from Fort Rozz when the team faces off with Reign.
In 'Fort Rozz', after Supergirl and Livewire track down Jindah Kol Rozz - while Imra and Psi remained on the Legion of Super-Heroes ship to deal with malfunctions brought on by a solar flare - the pair are confronted by Reign, who followed Supergirl to thwart her plans. Since Kara is left powerless, Livewire does most of the fighting. However, when Reign is poised to deliver a killing blow to Kara with her heat vision - because her powers are unaffected by the blue star - Livewire jumps in front of the blast and sacrifices herself for Supergirl.
Last week, Supergirl officially introduced the Legion of Super-Heroes, insofar as the show debuted their own take on a smaller version of the comic book team. Supergirl's Legion - consisting of Mon-El, Imra aka. Saturn Girl, and Brainiac 5 (Jesse Rath) - suited up to take on Reign while Kara was recovering from her injuries from her own battle with the Worldkiller. Though the Legion, with some help from the DEO and Supergirl, were able to eventually defeat Reign for a time, the Worldkiller continually proves to be a serious foe for Kara and her allies. Now that Reign has killed Livewire, it's no doubt raised the stakes for Kara.
Of course, Supergirl viewers who have enjoyed Morgan's portrayal of Livewire will no doubt be sad to see the last of Kara's sometimes-ally. Introduced as a villain in Supergirl season 1, the show has developed Leslie Willis into a compelling antihero of sorts, and a fun foil for Kara on the occasions that the two have teamed up. With Livewire sacrificing herself for Supergirl, the show has at least given the character a heroic sendoff.
Still, though Kara mourns Livewire, she'll have plenty to deal with as more Worldkillers are revealed on Supergirl. Next, the Girl of Steel will face off against Purity (Krys Marshall), who was introduced at the very end of 'Fort Rozz' as she saved her friend from being hit by a car. Meanwhile, Samantha is starting to realize she's losing time and enlists Alex (Chyler Leigh) to help figure out what's going on - but what will happen when she figures out she's Reign? That's a question Supergirl will need to answer as season 3 continues.
Supergirl season 3 continues next Monday with 'For Good' at 8pm on The CW.