A Demogorgon from Stranger Things, Marvel’s Scarlet Witch and Rick Sanchez from the animated comedy Rick and Morty were three of the intricately costumed fans invited to ask David Harbour questions at his Spotlight panel at New York Comic Con. The Golden Globe-nominated actor hosted an hour-long panel at Manhattan’s Javits Center, where he discussed his acting career in television, movies, and on stage. The candid conversation sailed through topics including Shakespeare and Stranger Things – and was sprinkled with secrets from season four of the hit Netflix series. Here are some of the edited highlights…

When did you realize that Stranger Things was going to be a success?

After I finished [filming the first season of Stranger Things], I came back to New York and I did Troilus and Cressida in Central Park, which is a very obscure Shakespeare play about the Trojan War. We opened on a Friday night, the night [Stranger Things] came out. At that point, I’d been an actor and people would recognize me a little bit from the movies I’d done, but I was not really that recognizable. On the Saturday night, 10 people were waiting for me after the show. And then we did the show on Sunday night and there were about 50 people waiting for me afterward. It was like: “What the hell is going on?” The next week, there were hundreds of people. It was crazy. And then I tore my Achilles tendon, thankfully. I got out of the play and I was laid up for a while, so people couldn’t find me.

How has Stranger Things changed your life?

I’ve been doing this professionally since I was 19 years old. I’ve had some successes and some failures, but I’ve never had an experience like this. Apparently, it takes 10 years to become an overnight success. That is the language in the business. It took me 20, but I’m a late bloomer.

How did the role of Sheriff Hopper come to you?

I was doing a television program that wasn’t very good, but I was desperate to pay my rent, so I wanted the show to get picked up for a second season. The week it didn’t get picked up, I was miserable and they sent me [the script for] Episode One of Stranger Things. I read it and I thought: ‘Wow, this is really good. I’ll never get this.’ I went in and auditioned, and a couple of days later we were on. I joke with [Stranger Things showrunners] the Duffer Brothers because apparently there was one person that was offered the role of Hopper before me; someone who was apparently a big movie star. Occasionally, when I am in such a self-hatred mood that I Google myself, an article will say: “Ewan McGregor was offered this part.” But I still don’t know who the actual celebrity is. If anybody knows, let me know so that I can thank them for passing.

How quickly did the show come together?

As soon as I auditioned, it was quick. They called me up and we sorted out the deal. It was me and Winona [Ryder] who signed on very quickly. She’s the best. The two of us were signed on early and they would send me the tapes of Noah Schnapp, Millie Bobby Brown, Caleb [McLaughlin], Gaten [Matarazzo] and Finn [Wolfhard] auditioning for different roles. They were like: “We think we’ve found our kids.” And they were so great. I couldn’t believe how good they were. I was really excited. We all went down to Atlanta and started shooting this crazy show that nobody knew about. We didn’t have any money and nobody cared about it. It was a really beautiful thing and it became what it is today.

Did you always know that Stranger Things would be a success?

I’ll tell you a funny story… I love Comic Con crowds because I know it will get out in some way – but I feel like I can tell you guys. Before I did Troilus and Cressida, I did a little Off-Broadway play with a guy named Paul Wesley from The Vampire Diaries. About a month before Stranger Things debuted, I was like: “Hey, man. There are no ads for my show.” He was like: “Oh, that’s weird.” And then, about two weeks before the show, I said to him: “There are still no ads.” He was like: “Sorry, man. They’re trying to bury it. It’s clearly a terrible show.” I was like: “Oh, no. I blew it. I had one of the leads in a Netflix show and I blew it. We all blew it.”

What can you tease about season four of Stranger Things?

There are storylines coursing through [the fourth season], one of which is me in Russia. From Russia with Love. I think the Duffers have talked about The Great Escape being one of their inspirations this year. You’ve seen that there is a Demogorgon in prison from last season. Well, I think they’ve also talked about Alien 3, which was the [David] Fincher Alien. So there’s an escape and there’s a ‘Hopper trying to get home to his family’ element to it, which is really incredible. And then you’ll see a lot more layers about Eleven [Millie Bobby Brown] and Brenner [Matthew Modine] and the Institute – and what she went through. And then there’s this new Creel House thing, which is a new element of a situation in Hawkins.

What other secrets can you reveal about the fourth season?

I think you’re going to see more development of the Joyce-Hopper relationship, which we’ve all wanted. And then you’re going to see more of the Hopper and Eleven development. To me, it’s the deepest season we’ve gotten to go with Hopper. And it’s the most self-aware. He starts to uncover these truths that we’ve only hinted at before, so it’s a really deep season and it’s got tremendous action to it. Action on a level that we’ve never done before, which is really exciting. I’m so sorry it’s taken so long. It’s going to be so good, though.