'Supergirl': SPOILER Dies in "Fort Rozz"

Supergirl took fans to "Fort Rozz" tonight, and not everyone made it out alive.

Major spoilers for tonight's episode of Supergirl, "Fort Rozz", below!

Tonight's episode saw Kara Danvers/Supergirl (Melissa Benoist) enlist an all-girl team of Imra Ardeen/Saturn Girl (Amy Jackson), Leslie Willis/Livewire (Brit Morgan), and Gayle Marsh/Psi (Yael Grobglas) to travel to Fort Rozz. The group was tasked with finding Jindah Kol Rozz (Sarah Douglas), who held information about defeating Samantha Arias/Reign (Odette Annable).

While there, Reign showed up to the proceedings, and proceeded to fight the quartet of ladies. Ultimately, she went toe-to-toe with Leslie, killing her in the process.

For Supergirl fans, this news might hit pretty hard, as Livewire has probably been the series' most prominent villain of the week. Leslie has been a pretty consistent facet of the show since its first season, earning quite a few fans in the process.

After making her debut in the appropriately titled episode "Livewire", Leslie returned in the Supergirl/The Flash crossover episode "Worlds Finest". She then returned in the episode "We Can Be Heroes", which saw Kara and Mon-El (Chris Wood) tracking her down after she escaped from prison.

So, how will Supergirl move on from this? As the end of the episode showed, Leslie's death is hitting Kara pretty hard, and making her further question whether or not she can get through to Reign. With the topic of a Reign redemption arc being floated around quite a bit (and somewhat being supported by Benoist), fans will just have to see how that develops.

Supergirl airs Mondays at 8/7c on The CW.