'Stranger Things' season 2 spoilers: Story to explore Eleven's background; David Harbour teases 'exciting season'

Promotional photo for "Stranger Things." | Facebook/StrangerThingsTV

Production for "Stranger Things" season 2 is in full swing, and cast member David Harbour recently revealed new details about the sci-fi drama's highly anticipated sequel.

Harbour, who plays Hawkins' Sheriff Jim Hopper, spoke with TV Guide, and he shared his thoughts on the next season's storyline. The actor noted that one of the biggest changes they will face this season is the amount of pressure in delivering a new installment that's as good as the previous one.

"We're completely terrified," he said during the 2017 Writers Guild Awards. "We want it to be even better than Season 1," he added. The publication clarified that when Harbour said "terrified," he was pertaining to his own expectations for season 2, and not that "Stranger Things" is going to have a scarier storyline.

In addition, the 41-year-old hinted that Hopper will be a changed man as he deals with the consequences of season 1. He didn't give away details about what's next for the police chief, but he said Hopper's story arc next season will be "rich" and "compelling."

Season 1 left off with Eleven (Millie Bobbie Brown) going to the Upside Down to save her friends, but fans certainly haven't seen the last of her. While Mike was seen mourning her death, the finale's last moments saw Hopper leaving Eleven's favorite Eggos in the woods. Mashable reports that season 2 will delve deeper into her history and background before she ended up in Hawkins.

New faces will also be introduced in the second season, including Joyce's (Winona Ryder) boyfriend and two young characters who will cross paths with the Hawkins kids. Dacre Montgomery and Sadie Sink are both heading to the small town, and they will play as step-siblings. Sink has been tapped to portray Max, who becomes a friend of the young boys, while Montgomery will play Max, her older brother.

The second season of "Stranger Things" will be released in its entirety on Tuesday, Oct. 31, on Netflix.