The official Stranger Things season 3 trailer was released this week to much fanfare, as we finally got a glimpse at what the Hawkins gang will be up against in the highly-anticipated new episodes.

While the action-packed trailer may have dispelled a few fan theories, it also launched a litany of more speculation about the Netflix series. A new theory, as reported by PopSugar, argues that one villainous character is more than just your average antagonist.

Near the end of the trailer, fans are introduced to a new monster, seemingly a replacement for the Demogorgon that wreaked havoc in the Upside Down and eventually the town in the previous two seasons. The appearance of the new, frightening creature left plenty of fans confused and frightened.

However, this new theory argues that while the monster looks totally unfamiliar, it’s not necessarily a new character. There’s a chance that Billy Hargrove—the callous bully and brother of Max, who was introduced to us in season two—is actually this scary creature.

The trailer reveals Billy has found a job as a lifeguard at Hawkins Pool. And while many viewers were focused on his abs as he strutted around, the theory takes note of the shot of Billy in the shower with a troubled look on his face as he examines some kind of red and black growth developing on his left forearm.

So, how did the nasty growth blossom? Well, the theory mentions the rat imagery and footage of rats running through a warehouse. And since rats can carry diseases, the theorist asks:

“What if the rats living underground in Hawkins got into those tunnels that Hopper and the kids were wandering around in under the pumpkin patch in season two are now carrying an infectious, Upside Down-borne illness?”

The red and black shades of Billy’s infection resemble the slimy vines that are in the Upside Down, so this isn’t a stretch. Moreover, the theory points out the close-up shot of Billy’s eye in the trailer, which has black tendrils reaching across his eyeball toward an extremely dilated pupil. This suggests he’s going through some type of transformation.

In the trailer, the monster appears to grow larger and larger in the hallway of a hospital, as Jonathan looks on in fear. “Judging from the way it expands on screen … it seems like whatever it is, it’s transforming from a human body into the creature that we see roar a few seconds later,” the theory reads.

They go on to hypothesize that Billy goes to the hospital to get his infection treated, but by the time he gets there, he has been overtaken by the demon creature.

This theory may sound a bit out there, but there’s definitely some visual evidence to back it up. We still have plenty of time to debate the matter, though. The new season of Stranger Things doesn't drop until July 4, 2019.