EW – At the heart of Teen Wolf‘s six seasons of supernatural villains, unexpected twists, romance, and lacrosse games, there has always been two people: Scott and Stiles. Together, they went looking for the body in the woods on the very night that Scott was bitten. Together, they fought Peter, Gerard, Deucalion, Kate, Peter (again), and a long list of others who tried to hurt the citizens of Beacon Hills. And together, they will say goodbye when the Teen Wolf series finale airs Sunday, Sept. 24 at 8 p.m. ET on MTV.

EW sat down with the actors behind Scott and Stiles — and real-life friends — Tyler Posey and Dylan O’Brien to talk about their time on the hit show.

ENTERTAINMENT WEEKLY: At what point did you all know this show was going to work, that it was going to be a hit?
TYLER POSEY: I had an intuition when we first started. During the pilot, it always felt right, it always felt good. There was just something about it that felt really interesting and its [success] wasn’t really a surprise to me. I always stayed grateful and thankful for everything so I was always excited, but it was never really too much of a shock. I’d say maybe the second Comic-Con, where we had a packed house, that was the first time where I really felt like we were making an impact and doing some cool stuff.

DYLAN O’BRIEN: Once I saw the first season, I just felt like it worked, I felt like the show had a lot of things going for it. When you work on something where you have such a great chemistry on set with our whole crew and cast, those things tend to unfold in a positive way. It translates to the screen. If you have a good thing going behind the scenes, you’ll have a good thing going on-screen. Once I saw the first season, I was so proud of what we did with it and how the season went. I thought it was a really good arc too and there was so much in the show to love — it was funny, it was scary, it was romantic. I was like, “Oh yeah we’ll totally get a second season.” Then it just kept going from there. It was something I always wanted to keep going and then it just became amazing how long it kept going for.

POSEY: It never stopped.

What about these characters and this world kept you engaged all these years?
POSEY: When you play a character for so long, it’s easy to get disengaged and it becomes mundane and routine. For me, the way that I made it interesting and fresh was: The scenarios and the writing were so far-fetched and so unrealistic for a lot of it that it was a challenge for me to try to make it as realistic and believable as possible. That’s what really kept it fresh. And constantly trying to change my character in subtle ways, growing him up and having him mature — that kept it fun.

For you Dylan, especially in the final season, you really had to work with scheduling to be a part of the show. Why was it so important to you to keep coming back?
O’BRIEN: This was my first role. I’ve loved Stiles since I read the pilot script, and throughout the series I only grew closer to him. I loved everything he got to go through too, everything [showrunner] Jeff [Davis] wrote for me, it kept it exciting. So I wouldn’t have missed it for the world. I always did everything I could to try to be a part of the show whenever I could, especially toward the end when it got difficult with everything else. Throughout [the series], it was always in the back of my head that this wouldn’t be around forever and that I would really miss it when it was over, so I was always conscious of that. I wanted to enjoy it while it lasted and enjoy working with T Pose while it lasted because we have just loved working together since day one and we’ve had so much fun on the show. We’ve built a lifelong friendship and he’s one of my best buds ever. So I was always aware of how special it was to me. I wanted to soak it up while it was around.

When was the show at its best?
POSEY: Story-wise, I think season 1. Season 1 had a really simple, relatable story line that was also just really fun, entertaining, and adventurous and dealt with sex, romance, horror. We were starting to dive into all of that. Every season of Teen Wolf was really cool and exciting and unique, but there was just something about the first season story-wise that was I think the coolest. Obviously, we grew to become a better show, whether it was visual aspects or directing and storytelling. We were really solid filmmakers toward the end of it, but the first season was just such a sweet, simple story line and show. I loved it. I thought it was so cute.

O’BRIEN: I’ve always felt like the show’s at its best when it’s fun. Whenever we took advantage of the humor and played toward that was when it was the most fun. That was the glue of the show in a way, because then that makes everything else fun to watch too. It makes it fun when it gets scary, and you care more when you see these kids in danger, or you just laugh. I think laughing’s such an integral part of the show, even when it’s scary. Humor and horror are linked in that way.

Do you feel satisfied with your characters’ endings?
O’BRIEN: At that point, it wasn’t as much about that. It was more about getting our last days on set with each other and our directors and our crew that we’ve grown so close with and these characters that we’ve grown so close with. It was almost just nostalgic — everyone celebrating the end of all these years that we’ve had together.

POSEY: That’s totally what it was. I feel like we kind of said goodbye to the characters a little while ago and so the last day was really just for us and was really nostalgic.

O’BRIEN: We’ve been anticipating it for a while so we’ve gone through a lot of mourning these characters. We’ve been aware that it’s going to go eventually and we’ve always wanted to just soak it up, so that last episode’s just fun to just do it one last time. It doesn’t really totally matter to me what happened.

POSEY: It was just a good time.