Ostensibly, Holden and the Roci will be set on their diplomatic mission by Avasarala in The Expanse season 4 premiere, but it’s Holden’s visions of Miller, speaking on behalf of the protomolecule, that drive him to go through the Ring to find out what happened to the ancient civilization that made interstellar travel possible. “For Holden, having this ongoing relationship with this ghost in his mind has become more normalized,” says Strait. “He’s accepted that this is part of his existence now. There’s no terror or shock or awe to what’s going on with him anymore. For him as a guy, he’s settling into the extraordinary circumstances that he’s found himself in, in a much more grounded way than we’ve seen in previous years… He’s finally at a place where the people around him have given him the support he’s needed over the years to actually become the leader he needs to be and they need him to be. For Holden, that’s where we find him at the beginning of season 4.”

Chatham admits that this normalization of Holden’s inner voice isn’t always easy for Amos. “He has somebody he’s really close to, that he relies on and leans upon, talking to dead people and ghosts,” says Chatham. “He believes Holden to a point, in the fact that everything that he’s said so far has been true and helped us, so he believes that. But he doesn’t necessarily know that he believes it’s Miller in there, and he doesn’t really know exactly what’s going on. There’s always the fear of, ‘Am I relying on a crazy person, and he’s just been right in the beginning?’ So going through this gate, depending on somebody that he’s really close with but doesn’t really know 100 percent where his sanity is, [Amos] is going to trust and be loyal to him and back him up in every way he can.”

Holden’s past has also informed his current situation, and the character’s evolution to this point has been very satisfying for Strait. “What I’ve loved so much about playing Holden is just how vast his arc is,” he says. “We you meet him originally, he’s this cocky, a bit arrogant, naïve guy who has literally run from the responsibilities of his life and found himself in the middle of fucking nowhere. Only through chance or fate, if you choose to believe in it, he gets pulled into this much larger world than he ever wanted or expected to be in and that he’s totally unprepared for. What’s been fun about playing him, to the best of my ability, is to portray a realistic ascent to heroism. It has not always been pretty; he’s had some really ugly turns. He certainly hasn’t always been the most likeable guy… but he’s always been vigilant.”

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But Holden has a unique and singular perspective based on his vision last season of the total extinction of the powerful race that made the protomolecule, making the ancient past almost as important as his personal past. “What he experiences in the station is about the most extreme dose of humility anybody could possibly ever get,” says Strait. “He not only gets an entire record of a civilization that is far more advanced and older than the one that he is part of and its place in the universe, but he understands how fragile not only he, but humanity is as a species. If something this advanced could be wiped out and they had no way of stopping it, what hope do we have on these few little rocks in the middle of the solar system?”