Stranger Things: A New Season 3 Trailer Hints at a Surprising Big Bad — Watch

We know Stranger Things‘ Demogorgon is scary as heck… but Season 3’s frights might come from someone a little more human.

A new trailer for the third season of Netflix’s retro sci-fi hit — which you can watch above — opens with an ominous voice declaring, “You let us in… and now you are going to have to let us stay.” Eleven thought she closed the gate to the Upside Down for good, but Will wonders, “What if we locked him out here with us?” And as he theorizes that the evil monster might “attach himself” to “a new host,” we see a shot of Max’s dreamy brother Billy looking, well, quite evil. Uh-oh… could he be the one to finish what the Demogorgon started?

Related stories

Stranger Things' New Season 3 Teaser Flaunts a Sexy 'Showtime' in Hawkins

Summer TV Calendar: 100+ Premiere and Finale Dates to Save!

The Prom: Meryl Streep, Nicole Kidman, Ariana Grande and More Join the Cast of Ryan Murphy's Netflix Movie

Elsewhere in the new footage, we see: Jonathan grabbing an axe and Nancy cocking a shotgun to battle the evil invasion; big showdowns at an amusement park and inside a shopping mall; Eleven vowing to fight, but Hopper assuring her, “I need you safe”; Steve examining a mysterious vial of glowing green goo; and that same ominous voice promising, “We are going to end you, we are going to end your friends… and then we are going to end everyone.”

Don’t forget to cancel your barbecue plans: Stranger Things returns for Season 3 on Thursday, July 4. Press PLAY above for a sneak peek, and then hit the comments below with your theories and predictions.

Sign up for TVLine's Newsletter. For the latest news, follow us on Facebook, Twitter, and Instagram.