David Harbour, who plays Hopper on Netflix's Stranger Things, discussed what to expect from Season 4 and his character, during Liverpool Comic-Con as reported by IndieWire.

Stranger Things, David Harbour, Season 4Dia Dipasupil / Getty Images

The actor says to look for more backstory for Hopper, referencing a scene from Season 2 in which Eleven discovers boxes labelled "Dad," "Vietnam," and "New York"

"So there are these three things that we've established in the season that if we don't pay off, it means that they're bad writers, and the Duffer brothers are very good writers. So I know specifically that in Season 4 we will give you a big, huge reveal about Hopper's backstory.

"It's my favorite thing about him that you guys don't know about him yet, but it has to do with these backstories of New York, Vietnam, and dad," he continues. "And I'm really excited for you guys to know more about that, and it relates, of course, to things he's doing with Eleven and Joyce and things like that."

Joe Keery also spoke about Season 4 expectations recently, saying the show will get much darker: “I think that this year — and I know I say this every single year — but this is definitely going to be a lot scarier than prior years, because last year was pretty dark."