Max is in grave danger... and running out of time. A patient at Pennhurst asylum has visitors. Elsewhere, in Russia, Hopper is hard at work.

Owens takes El to Nevada, where she's forced to confront her past, while the Hawkins kids comb a crumbling house for clues. Vecna claims another victim.

Behind the Iron Curtain, a risky rescue mission gets underway. The California crew seeks help from a hacker. Steve takes one for the team.

As Hopper braces to battle a monster, Dustin dissects Vecna's motives — and decodes a message from beyond. El finds strength in a distant memory.

Nancy has sobering visions, and El passes an important test. Back in Hawkins, the gang gathers supplies and prepares for battle.

With selfless hearts and a clash of metal, heroes fight from every corner of the battlefield to save Hawkins — and the world itself.