'Stranger Things' Season 4 to reveal origin of The Upside Down

"Stranger Things" Season 4 is going to reveal the origin of The Upside Down as the showrunners, The Duffer Brothers, say the installment will "connect everything" to "something long buried."

The Duffer Brothers released the teaser trailer for "Stranger Things" Season 4 along with some hints about what fans can expect from the story. In a statement shared by several online publications, the creators spoke of a "new horror" that is "beginning to surface, something long buried, something that connects everything."

This horror happens back in the United States where the gang is at, but likely not in Hawkins. Perhaps it happens where Eleven has relocated with the Byers family.

According to Fansided, the creators' statement suggests that "Stranger Things" Season 4 is going to get to the bottom of everything that has happened since Season 1. Fans may finally see the events or the reasons that led Dr. Brenner to experiment on children with powers (Eleven and the other Hawkins test subjects).

The installment could go as far back as to trace the origin of The Upside Down. There has got to be something that started it all.

"Season 4 is shaping up to be the biggest and most frightening season yet, and we cannot wait for everyone to see more. In the meantime, pray for the American," The Duffer Brothers said in the statement.

Outside of the new horror that awaits the team back in the States, the creators also teased the presence of something sinister in Kamchatka. The teaser trailer for "Stranger Things" Season 4 confirmed the return of Chief Jim Hopper (David Harbour) as the captive American teased in the Season 3 end-credits scene. Apparently, Hopper is still not safe from the monsters that he tried so hard to avoid back in Hawkins.

"Although it's not all good news for our 'American;' he is imprisoned far from home in the snowy wasteland of Kamchatka, where he will face dangers both human...and other," the creators teased.

Filming for "Stranger Things" Season 4 is well underway with Lithuania being the first production location before continuing in Atlanta, Georgia until August. Netflix has yet to announce the show's premiere date.