Alberto Rosende, who plays Simon on ABC’s Shadowhunters, exclusively discusses with us his role on the show and what we can expect from his character moving forward.

In the interview below, Rosende previews tonight’s episode, “Dead Man’s Party,” as well as his character’s relationships with Katherine McNamara’s Clary and Emeraude Toubia’s Isabelle. Be sure to check out our other interviews with Toubia and Maxim Roy.

Simon is definitely a fan favorite. What has the process been like for you preparing to be Simon and finally having the fans see the show?

I know one thing I was very worried about when I got the role was, “Am I going to be the person that the fans see as Simon?” Because I know one thing with books you have to be very careful about is everyone gets a picture of who these people are, so I knew I couldn’t please everyone. And I knew I had to find who Simon was for me and hope that truth in the center of who Simon was [meant] I could bring that out and everyone could agree with that [version]. And I hope I did that. And I know that in order for me to feel that I did that, I read all the books. And I had to make sure I understood him completely. I started listening to a lot of music. I started really trying to dive into the world that he very much lives in. And I hope that work paid off. I feel that it did for me. Just being Simon, I felt like it made me understand who he was. And it made me understand how he feels about certain things. Honestly, I think I became friends with Simon.

Simon has taught me a lot. Simon’s kind of nerdy and geeky, and I feel that being able to hang out with him and be on set with him, it’s kind of let me unleash my inner geek, my inner nerd. And I really appreciate that.

Describe Simon’s relationship with Clary and what it’s like for him to see her with Jace, become a shadowhunter, and so on. How much has his world changed?

His whole understanding of how the world works has been shaken to its foundation. He had this very clear image of how the world worked, and then to come into another world that coexisted with his world his whole life makes him not understand anything but want to understand everything. He’s both extremely fascinated and excited about the possibility of this new world, but he’s also extremely frightened by it because he knows it’s a world that possesses real danger in a world [where] things can really go wrong. And in the next episode he really gets a firsthand look at that world and everything it really has to offer.

Last week we had our first look at Simon and Izzy’s interesting dynamic, which fans refer to as Sizzy. What was it like to film those scenes with Emeraude? Can we expect any major Sizzy scenes in upcoming episodes?

At first it was really cool. I tried to actually…not stay away from [Emeraude], but for the first few scenes, I wanted to make sure that Simon meeting Isabelle was as new and organic as possible. So when we were on set, I talked to Emauraude, but I tried to kind of keep a distance so when [Simon] did get to meet her for the first time it was brand new. And it was very fun because there’s definitely a spark that happens in the second episode when Simon and Isabelle first meet. But as far as the books go, and our relationship as Sizzy, it’s a slow burn. They both have to grow into better versions of themselves in order to be together. And I think you kind of see the beginning of that understanding and trust, and the beginning of that build and the beginning of their growth before that. And you see that throughout the rest of the series, but nothing too big. But there’s definitely some other moments that are very good.

What can you tease us about the next episode, “Dead Man’s Party,” or Hotel Dumort?

I can tell you that Simon gets a really firsthand understanding of the Downworld, and more specifically of vampires and how they operate. I can tell you that his experiences in Hotel Dumort traumatize him and stick with him for the rest of the series. It’s the first time he understands the danger that Clary’s really in. That definitely stays with him. It’s the first step in him becoming more a part of that world.

Finally, what aspects of Simon and his story are you excited to explore that we didn’t necessarily get in the book?

In the books it felt as though Simon was very much…not opposed, but had a very hard time coming to terms with the Shadow World and the Downworld and everything that happens with him in these two worlds that he’s trying to exist in. And in our [show] you see him really try to explore and understand the whole world that Clary has become a part of. In our show you really get to see him try to become a part of it a little bit more in a way that he tried to stay away from it in the books.

What do you love most about Simon on ‘Shadowhunters’?