Millie Bobby Brown Reveals Which Unexpected Stranger Things Costar She Found 'Really Hard to Let Go'

Netflix

No thanks to Stranger Things' unflinching ability to break hearts by killing off its characters, Millie Bobby Brown is used to saying goodbye to costars.

But the 18-year-old actress does admit it took her a little longer than usual to get over a few of the show's dramatic deaths.

"It sucks sometimes," Brown admitted to Entertainment Tonight. "I loved Billy. I loved Dacre Montgomery, who was killed off in season 3. I had a really good relationship with him, so for me, it was really hard to let go of that."

She continued, "And the same thing with Papa [Matthew Modine] in this season. I had a really good relationship with Papa. I had a really good relationship with Matthew, and to let him go was really hard."

RELATED: See the Stranger Things Kids' Adorable Audition Tapes Ahead of the Series' 2016 Premiere

Netflix

As the show's final season looms on the horizon, fans have already theorized about which characters may die — and which, if any, could return from beyond the grave. One major fan theory supposes Eddie Munson (Joseph Quinn, whose character died a heroic death in season 4) could reappear — though this time as a fighter for Vecna and in his mission to destroy the world.

RELATED: Everything to Know About Stranger Things Season 5

Though Brown didn't offer any specifics about what season 5 might hold, she did acknowledge, "I mean, it's a good fan theory."

There's no release date yet for Stranger Things season 5, but there are many questions left without answers.

The biggest is the fate of Max Mayfield (Sadie Sink), who nearly died at the hands of Venca in season 4. Max was comatose in the hospital at the end of the season, and there's reason to believe she could be permanently blind even if she doesn't die.

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All four seasons of Stranger Things are currently available to stream on Netflix.