32 Very Important Details We Noticed in the Totally Insane Stranger Things Season 3 Trailer

In a very quick sequence in the trailer, we see a bunch of hazmat-suit-wearing scientists observing a reactor of some sort, before it explodes with bright blue light and energy. One man in particular is knocked back into the air, and we see bursts of red blossoming all over his suit — is he merely being singed by the blast, or is that the red glow we've come to associate with the Upside Down? If we had to bet, we'd say that reactor (or whatever the hell it is) is located below the mall, and the explosion triggers a series of reactions in people in Hawkins.