Stranger Things has released the trailer for the second volume in the fifth and final season of the show, and the stakes have never been higher in Hawkins, Indiana. Our heroes learn that what they thought they knew about the Upside Down is all wrong.

The first four episodes of Stranger Things season five saw Eleven (Millie Bobby Brown) training to fight Vecna (Jamie Campbell Bower), and Hopper (David Harbour) making trips to the Upside Down to find him. It was revealed that Max (Sadie Sink) was still alive in a prison constructed by Vecna, that Eight (Linnea Berthelsen) was being held captive by the military, and that Will (Noah Schnapp) shared a connection with Vecna.

The trailer begins in the aftermath of the Volume 1 finale when Will tapped into that connection to telekinetically save his friends from the Demogorgons. Max and Holly (Nell Fisher) try to find a way out of Vecna’s world, and Eleven asks the newly freed Eight to help her find and kill Vecna.

There’s some kind of swirling ball of energy in the Upside Down and a wave of lightning that travels across the sky. One team breaks into the military base, where Nancy (Natalia Dyer) openly fires at Dr. Kay (Linda Hamilton) and her forces. Demogorgons attack the hospital, Vecna transitions between his multiple incarnations, and in a dramatic moment, Steve (Joe Keery) and Dustin (Gaten Matarazzo) promise each other “If you die, I die.”

Stranger Things season five also stars Finn Wolfhard, Caleb McLaughlin, Winona Ryder, Charlie Heaton, Maya Hawke, Brett Gelman, Priah Ferguson, Vickie Amybeth McNulty, and Cara Buono.

The next three episodes – titled “Shock Jock,” “Escape from Camazotz,” and “The Bridge” – will debut on Netflix on Christmas Day. The series finale will stream on New Year’s Eve.