Netflix has released a trailer for the Stranger Things finale

Tomorrow's the big day, and I don't just mean New Year's Eve. The series finale of Stranger Things airs tomorrow, and Netflix has released a trailer for the last episode. We're given only flashes of the final episode, along with a voiceover of an emotional Jim Hopper telling Eleven he needs her to fight one last time.
It's just over 1 minute and 30 seconds long, with what appears to be only about 30 seconds of new footage. There isn't much to go on here, as most of the footage features emotional moments from seasons past. Netflix no doubt is hoping to keep much of the excitement under wraps until tomorrow's premiere.
Warning: Some spoilers ahead for Stranger Things season 5.
Among the new images we briefly see Vecna, hooked up to the ceiling in his gross cave of power on his other world. There's also an explosion at what looks like a military site, plus a few more out-of-context flashes of our heroes.
One particularly ominous moment shows Hopper walking