After attending a wedding and a movie premiere, Dev and Rachel have to face up to all kinds of issues between them.

God asks Sanjay to smite a non-believer, while Craig and Eliza realize they have their work cut out for them.

A code red brings the gang back together to face a frighteningly familiar evil. Karen urges Nancy to keep digging, and Robin finds a useful map.

Dustin adopts a strange new pet, and Eleven grows increasingly impatient. A well-meaning Bob urges Will to stand up to his fears.

After Will sees something terrible on trick-or-treat night, Mike wonders whether Eleven’s still out there. Nancy wrestles with the truth about Barb.

As the town preps for Halloween, a high-scoring rival shakes things up at the arcade, and a skeptical Hopper inspects a field of rotting pumpkins.

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.

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.

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.

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.

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.

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.

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.

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.