An unlikely hero steps forward when a deadly development puts the Hawkins Lab on lockdown, trapping Will and several others inside.

Eleven makes plans to finish what she started while the survivors turn up the heat on the monstrous force that's holding Will hostage.

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.

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.

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