Joe Holt, who plays Dr. Leo Bennett on The Walking Dead: World Beyond, talks about Leo's relationship with Hope and Felix, why he went to help the Civic Republic and what it was like experiencing the night the sky fell.

Q: Why did Leo decide to help the Civic Republic, even if it meant leaving his daughters behind? 

A: I think that Leo is a scientist at heart and he believes in that process and he also believes in the greater good, and sometimes that requires personal sacrifice. So I think that, when he was called upon, he feels the responsibility to provide answers that could, not to put too fine a point on it, but that could save the world. And I think that's obviously part of the conflict between a father and his daughters or sons as it were, that it's almost as though I've had a greater calling and I owe it to everyone, to the world, to myself, to the kind of oath you take as a person of science -- sort of like a doctor takes a Hippocratic oath, whoever is put in front of them they have to operate on -- so I feel like he just felt a sense of duty to serve the greater good.

Q: Can you talk about the dynamic between Leo and Hope in Episode 4?

A: I think that, as with any children, both of the kids represent parts of Leo, and I think that Hope has a tremendous mind that she kind of rebelled against. She's incredibly bright. She's a great problem solver. I think she is a natural scientist, but I think she's also a rebel and she's also at that age where kids rebel and try to distinguish themselves. I feel like [Hope and Leo] have a real bond and that's where [they] bond. I think their brains work very similarly actually, and, not to speak for her character, but I think that she has a pessimism about what's going on -- which I always feel like is a result of truly being an optimist because it hurts so much that negative things are happening that you take on that cynicism.. because I think she is a romantic at heart.

So I feel like the relationship really hinges on this mutual love of problem solving and I think their both kind of romantics who have been given these very pragmatic problem-solving kinds of brains. I think outwardly [they] are polar opposites. She is a rule breaker and she will not be guided or told what to do, and [Leo] is a person that is following the scientific method. He is an A leads to B leads to C, and there is a way you do things. So I always feel like that rebellion, that difference is where the conflict comes from, but I think it is underscored by a true understanding of one another on a very deep level.

Read More: Q&A With Alexa Mansour (Hope)

Q: Why does Leo choose Felix to protect his family?

A: The things that I see in Felix are loyalty, resolve and an ability to survive. [Leo] would never have brought him along if he didn't see those things in this kid who life dealt a tough blow. And so [he] has ultimate trust in this guy, and he's proven to be resilient, he's proven to be resourceful and he's proven to be loyal, so essentially he thinks of him almost as a son. And he's the only person that [he] knows there that [he] would trust my daughters' lives with. He cares about them, and I think that he takes that duty seriously. He feels the responsibility -- again, not to speak for another person's character -- but I get the sense that he feels a responsibility not to let [Leo] down.

Watch: Nico Tortorella on Felix:

Q: What was it like shooting those scenes flashing back to the night the sky fell?

A: That was my first episode, and there was a lot going on. For me, it was like shooting a feature film with effects and airplanes and explosions, and we were basically almost literally thrown into the fire with me and my two younger daughters and my wife. I felt like it was actually very useful because, of the four of us, I was the one that's had the most experience on set, and so I immediately felt like it was my job to protect and guide if there was any negative energy that might have been coming just from the hustle and bustle and the anxiety of being on set, like it was my job to shield them from that and shepherd them to some degree. Not that they needed it -- my daughters and my wife were all professionals and fantastic actresses, all of them. It was a great introduction for me to the show for reasons that are both personal and practical and professional. As a guy that doesn't have kids in real life, it just informed everything. That's exactly who Leo is. That's who Dr. Bennett is, someone who is doing his best to shield his family from the horrors, and I think that what happened on that night clearly affects him in many ways today.

There was a surreal element to running through the streets of this town that has been carved out for us and the special effects were amazing. The effects team is amazing. The explosions. All these crew members just working through the night, trying to create this sort of bedlam... For me, it was really one of the first times in my career that I just decided to fully be present, go with the flow and discover the journey along... So it was crazy but it was terribly enjoyable.

Q: In the post-credits scene, we learn that Leo is acquainted with both Dr. Bellshaw and her test subject, Dr. Abbott. What do you make of these kinds of experiments?

A: There probably are some ethical questions of we need to do this thing because the potential outcome will save more lives than this act might harm. And these are calculations, right? Is it worth four people dying if 100 will survive? And while it's easy to say, "Yes of course it is," what if you're the person making the decision?

Q: What can you tease about what's coming up for Leo in the rest of the season?

A: Leo's primarily in flashback... so I think that where is Leo now is kind of the question...

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