A new trailer for the second season of the popular sci-fi, mystery Netflix series, "Stranger Things" will feature Eleven's return and the town of Hawkins possibly being invaded.

Invasion from the Upside-Down World?

The new trailer for "Stranger Things" season 2 was shown at San Diego Comic-Con, as the video will see the four boys from Hawkins, Indiana: Will Byers, Mike Wheeler, Dustin Henderson and Lucas Sinclair going to the arcade playing the video game, "Dragon's Lair."

As the boys are having fun, Will noticed something strange outside the arcade.

When Will turns around, everyone is gone as he is suddenly transported to the "Upside-Down" world and sees a gigantic creature. He is then shifted back to the real world. Fearing that experience from the other world still haunts him, Will and his mother, Joyce tried to examine what is happening to his body and he starts seeing horrific things coming from the Upside-Down world.

The trailer is accompanied by Michael Jackson's "Thriller," as boys prepare for Halloween, while several weird things are happening in Hawkins. They are somehow connected to Will as the rest of the townsfolk including Chief Police officer Jim Harper, Jonathan Byers, Nancy Wheeler and Steve Harrington armed themselves for a possible invasion.

Cast member Noah Schnapp hinted in an interview that his character will be "traumatized" after his abduction from the Upside-Down world during the first season. There are also numerous speculation that Will could exhibit powers and even turn "evil" due to the effects from the other world.

Other rumors suggest that Will could be mutated from the Upside-Down world, and possibly become the new Demogorgon in the show.

Eleven returns to Hawkins

Perhaps the most shocking part of the "Stranger Things" season 2 trailer is the return of Millie Bobby Brown's character Eleven to the show. The trailer show's Eleven on the other side after she sacrificed her life to save Mike and others from the Demogorgon, the monster that abducted Will and killed Barbs.

Eleven searches a way out from the Upside-Down world and discovers an opening from Will's school. Eleven's return was first speculated in episode 7 of the second season titled "The Secret Cabin." She is also hinted to be the key to Will's growing effects from the other world, having a much bigger role in the show.

The second season of the show will also feature new characters such as the new girl Max, who are played by "American Odyssey" actress Sadie sink. Max' brother, Billy will be played by "Power Rangers" movie actor Dacre Montgomery.

"Stranger Things" season 2 will premiere on Oct. 27 on Netflix.