Stranger Things Season 5 Brings Back The Show's Most Divisive Character

The following post contains major spoilers for "Stranger Things" Season 5, Volume 1.

We've already turned our attention to the new faces that have joined "Stranger Things" in its final season. But there's also a familiar one that we never thought we'd see again.

Throughout the first four episodes of Season 5, which are now streaming on Netflix, Eleven (Millie Bobby Brown) and Hopper (David Harbour) discover that 1) there's a military base in the Upside Down, and 2) that base is housing something — or, more likely, someone — so powerful that they're locked away behind a massive door.

At first, Eleven is sure it's Vecna behind that door. Who else would make sense, if it's someone with special abilities in the Upside Down? But in a major scene toward the end of Episode 4, Eleven and Hopper learn it isn't Vecna at all: It's Kali, aka Eight, Eleven's fellow test subject and "sister" from Season 2.

Of all the characters that could have returned to "Stranger Things," Kali is perhaps the most polarizing. During Season 2, she was introduced as one of several children on whom Hawkins Lab had experimented, with Kali gaining the ability to warp how others perceive reality. Wanting to know more about her own powers, Eleven met up with Kali and other gifted individuals during the show's sophomore season, in a much-maligned arc that found Kali attempting to weaponize Eleven's abilities in order to kill those who had hurt them both.

Kali & Co. weren't seen again after Eleven parted ways with them, leaving us to suspect the "lost sister" storyline had been dropped for good after criticisms against it — but the final season has revealed something else entirely. Kali now appears to play a major role in the "Stranger Things" endgame; when Hopper and Eleven finally get beyond that door at the Upside Down's military base, Eleven is stunned to see Kali hooked up to all kinds of wires and IVs, her head now shaved. Kali recognizes Eleven and smiles at her, but her presence at the military base is left to be explored further in Parts 2 and 3 (releasing Christmas Day and New Year's Eve, respectively).

Were you shocked to see Kali return to the "Stranger Things" fold so late in the game? Hit the comments with your reactions!