'Stranger Things' season 2 debuts on Netflix today

See what you should expect from season 2.

Star David Harbour, who plays Police Chief Jim Hopper, says in a promotional video from Netflix that anyone who might have avoided season one because they heard the show was science fiction ought to reconsider with season 2.

"We're really creating a world of real, ordinary people who are struggling to go through life, and then you get the added benefit of, like, a monster popping up," Harbor said.

A star of the show, Natalia Dyer, who plays teen sister Nancy Wheeler, says the new season finds all the characters struggling to cope with the events of season one.

"I think we see everyone looking for that new normal ... just trying to keep on carrying on, find safety, find normalcy," she said. "But we know there's no really going back to where they started. So we kind of see that begin to unravel in the beginning of season 2."

No one is unraveling more than Will Byers, who spent most of season one lost among scary creatures in the alternative universe called the "upside down."

Show co-creator Matt Duffer describes Will's mental state at the start of season 2.

"He has this vision of the upside down and a storm in the upside down, so the question is, 'Is that in his head? Does he have post-traumatic stress disorder? Is he having hallucinations? Or is it something real?'" Duffer says.

With "Stranger Things," it's probably safe to assume that there's something real, and nasty, coming the way of our heroes.

"Something clearly is out there that's coming back in a bigger, badder way for this season," Harbour said.

"Stranger Things" is now streaming on Netflix.