On his way home from a friend's house, young Will sees something terrifying. Nearby, a sinister secret lurks in the depths of a government lab.

Lucas, Mike and Dustin try to talk to the girl they found in the woods. Hopper questions an anxious Joyce about an unsettling phone call.

An increasingly concerned Nancy looks for Barb and finds out what Jonathan's been up to. Joyce is convinced Will is trying to talk to her.

Refusing to believe Will is dead, Joyce tries to connect with her son. The boys give Eleven a makeover. Nancy and Jonathan form an unlikely alliance.

Hopper breaks into the lab while Nancy and Jonathan confront the force that took Will. The boys ask Mr. Clarke how to travel to another dimension.

A frantic Jonathan looks for Nancy in the darkness, but Steve's looking for her, too. Hopper and Joyce uncover the truth about the lab's experiments.

Eleven struggles to reach Will, while Lucas warns that "the bad men are coming." Nancy and Jonathan show the police what Jonathan caught on camera.

Dr. Brenner holds Hopper and Joyce for questioning while the boys wait with Eleven in the gym. Back at Will's, Nancy and Jonathan prepare for battle.

El is bullied at school. Joyce opens a mysterious package. A scrappy player shakes up D&D night.

A plane brings Mike to California — and a dead body brings Hawkins to a halt. Nancy goes looking for leads. A shaken Eddie tells the gang what he saw.

Murray and Joyce fly to Alaska, and El faces serious consequences. Robin and Nancy dig up dirt on Hawkins' demons. Dr. Owens delivers sobering news.

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.