Stranger Things 3 Trailer Breakdown: 13 Things You Need To See
5. Billy's Contracted Something...
In a brief shot late in the trailer, we see Billy examining a black, infested spot on his arm. Stranger Things being what it is, this is almost certainly something from the Upside Down that has quite literally sunken its teeth into Billy's arm.
While we've seen characters be possessed by creatures from the Upside Down before (see: Will in season 2) we've never really seen this kind of infection happen before, suggesting that despite this trailer's heavy emphasis on good times and summer vibes, all is very, very far from fine in Hawkins.
If you'll indulge me and put on your tin hats for just a moment, I think there's actually a fairly solid chance that Billy's infection here winds up morphing him into the new monster seen at the end of the trailer. This kind of thing happens in D&D frequently, so it's certainly not out of the realm of possibilities, and Jonathan looks like he's watching something transform into that hideous beast.
That something may just be the biggest douche in Hawkins, Billy Hargrove.