The Expanse has been holding out for a hero.

Ever since Holden — along with Naomi, Amos and Alex — survived the destruction of the Canterbury, this ragtag crew has been navigating the political struggles between Earth, Mars, and the Belt. They've faced unspeakable dangers, including the havoc-wreaking protomolecule. Ultimately, Holden found that alien life form appearing to him in his head, offering information and guidance. And, even though Holden acts as the captain of his ship, he's never fully embraced the role of a leader. Until now.

The Expanse's third season culminated with the opening of the Ring Gates and access to hundreds of inhabitable planets. When Season 4 kicks off on Amazon on December 13, Holden and the Roci team venture to a world called Ilus to help settlers and, once again, keep the peace. However, new obstacles and rising tensions threaten this existence. And, to make matters even worse, Holden and the protomolecule Miller may be responsible for Ilus' most epic crisis to date.

Steven Strait (Sky High, The Covenant) who plays Holden, recently spoke with SYFY WIRE in Toronto, where he discussed Holden's journey from zero to hero, his complicated relationships, and getting a handle on ProtoMiller.

Video of The Expanse Season 4 - Official Trailer | Prime Video

Holden never wanted to be the leader or hero, but once again he's thrust into being the peacemaker on Ilus. How comfortable is he in that position?

At this point in the story, he's certainly more comfortable in it than he ever has been before. One of the great joys of playing Holden is the scope of his arc over the course of five years. We see this man who is very naïve when we first meet him. His world view is quite black and white, and pretty narrow. Through his experiences, and through not living up to his own expectations most of the time, he becomes a stronger, more competent leader through humility, which is a really lovely arc to play… and an unusual arc to play.

For me, as an actor, to be able to show the evolution of a leader who has earned his place with his feet on the ground by season 4, and certainly by Season 5, has been an amazing long-term story arc to collaborate on.

The Expanse's Holden and Naomi

This year, Holden and Naomi have had to spend a lot of time apart. Will that put any strain on their relationship?

In a certain sense, it's a challenge in the relationship. The thing with the Roci crew, having these strangers find themselves in this situation in Season 1, they don't really know each other all that well. They are on the same ship, but they are not close. They do get to learn about each other through this story. Playing at an arc that is unique — Holden and Naomi come together essentially clutching this maelstrom of insanity that's going on around them — they find comfort in each other going through these experiences.

The nature of their relationship is not solely romantic. It's also a business endeavor. Holden is technically the captain of this ship, but it really kind of functions as a democracy. Naomi's opinion is one that he trusts more than anybody. She's certainly the smartest person on the ship and he really relies on her, not just within the functioning of the Roci crew getting things they need done, but she's his bedrock, especially as he's going through the beginnings of that prophet-like turn where he really doesn't know if he's going mad or not.

Naomi is the one who holds things together. It's been interesting to play with those colors because it's not a normal arc for a relationship on television.

Another fascinating relationship is between Chrisjen (Shohreh Aghdashloo) and Holden, because they are different characters who have, so far, mostly ended up on the same side of a situation. She's the one who sends them to Ilus at the beginning of Season 4. Can you talk about how you see that relationship and how it might change over the course of the season?

It is a very unusual relationship. As an actor, what a joy it is to be able to work with someone I've looked up to so long — I remember seeing her in House of Sand and Fog — Holden's relationship with the Powers that Be is interesting. It is complex because they are not affiliated with anyone. Over the years, he's had relationships with the head of UN, the head of the OPA, depending on what's necessary. You have Fred Johnson. You have Avasarala. You have all these different people that he's had transaction-based relationships with.

At the beginning of Season 4, she allows him to go through after he's asked 100 times. Again, for mutually beneficial reasons. He gets there not necessarily to help Earth's cause there. He's not with the RCE. He couldn't give a s*** whether or not they get their lithium. But, the protomolecule is of deep importance to him. Not only because he's being haunted by it, but he understands what the ramifications from not dealing with it are. And, every once and a while, the Greater Powers' interests align with his. And, it does at the beginning of Season 4. She allows him through the blockade.

Credit: Amazon

In Holden's search to get answers about the protomolecule, he puts some faith into ProtoMiller at the beginning of Season 4. As a result, there are some pretty intense and devastating consequences. Can you talk about how his dynamic and the way he views ProtoMiller evolves this year?

The ProtoMiller arc was one of the things I was most looking forward to portraying as a fan of the book. It's such an unusual set of circumstances to build a relationship on. The foundation of it at the end of Season 3 and into Season 4 is not solid footing. He doesn't really know what the Investigator is. Is ProtoMiller really Joe Miller's consciousness? Or, is he really a projection that this machine is using to allow him to understand what it wants? And, very early on, is Holden going crazy? Is he going mad? The truth is the extreme situation at the end of Season 3 forces his hand. Holden has no choice but to trust him. He has built a relationship with ProtoMiller through these experiences.

By the beginning of Season 4, two things have happened. One, Holden has become more comfortable with the fact that he's become this prophet-like figure. The relationship with ProtoMiller is very casual at this point because he sees him all the time and he's constantly asking him for what it wants, over and over and over again. But there's something off. The projection is repeating.

When they get through the Ring and the "Wi-Fi" gets better, Holden trusts him until it blows up in his face. The prospect of him being used by the protomolecule is a very real and apparent danger, not just to him, but to everyone else on Ilus and possibly everyone beyond the Rings as well. It is a deeply complex set of meanings for Holden to understand what ProtoMiller is to him, whether he knows what it is or whether it even matters whether he knows what it is. But, certainly, when it starts creating situations where everyone he is responsible for is in peril, he pushes them away, in a lot of ways.