The Expanse Season 4 Ending Explained

As is typical with The Expanse, the ending moments of season 4 represent a narrative shift to prepare for a new story arc in season 5, following the same natural borders presented by successive novels in the James S. A. Corey series upon which the show is based. With the protomolecule no longer a factor, at least as it applies to Miller and the search for what happened to the Builders, it appears that a larger alien threat looms in the future: the superior force that killed the already powerful and advanced civilization that created the galaxy-spanning transport system of gates. And that’s not even taking into account what Marco Inaros has planned for Earth!

In fact, let’s start with the explanation of what Marco accomplished through sabotage, piracy, and black marketeering. Much was made of his charismatic power, and that and the strength of his conviction that Belters must throw off the yoke of oppression by the Inners was enough to save his life among his peers. But Ashford was right to hone in on his statement, “Mars isn’t what it used to be.” By all appearances in the finale, Marco’s terrorist faction was able to obtain MCRN stealth tech to apply to the surface of several asteroids which will be not be set on collision courses with Tycho or Ceres as Ashford surmised, but with Earth itself.

That’s why the hijacked UN colony ship Sojourner was aimed at the asteroid defense system of Earth earlier in the season: to test its capabilities and vulnerabilities. And if you look closely during the botched deal with Beltran on Mars, the one that was supposed to make corrupt cop Esai Martin and his cronies rich, you can see Filip Inaros, the son of Marco and Naomi who is identified late in the finale, flipping off Bobbie just before the place explodes in a shower of glass. This shows that the Belter terrorists also have access to Navy frigates similar to the Rocinante to transport their black market military goods, including the stealth technology. This level of acquisition can’t be explained by a few cops on the take!

And that’s why Bobbie contacts Avasarala for help. Someone high in the Martian military placed Beltran in a position to offer the too-good-to-be-true deal, and Bobbie wants the Secretary General’s help taking down whoever has sullied the previously unassailable reputation of the MCRN. But not only is Avasarala not in charge of the UN anymore, Bobbie has also learned that the people of Mars as a culture are no longer interested in maintaining the terraforming efforts now that they know that so many ready-to-go planets are available through the Ring gates, so there’s not much to prevent the slow degradation of Martian society and of the moral fortitude of those in power. As to what the higher-ups have to gain from selling off their proprietary gear to Belters, only readers of the books know the answer to that… for now.

But what do we know about what happened on Ilus? Why did Holden have to follow Miller (who was gloriously back to his snarky season 1 self) deep underground to an area that was undetectable and invisible to the protomolecule? The detective was eager to die once and for all and put the souls of Eros, still swimming in a tortured soup of souls inside the blue goo, to rest, and this dark orb was a remnant of whatever killed the Builders off millennia ago and presumably could do the job once more. But Miller had his hands full maintaining human consciousness and taking physical form inside a patchwork metal body in order to lead the protomolecule intelligence to its own oblivion; someone else had to guide him to the spot he couldn’t see. The fact the Elvi Okoye ended up doing it instead of Holden only means she may end up gaining the alien perspective she so coveted.

In fact, Elvi mentioned that when she passed through the orb she “could feel the spaces between things — something was there, a presence moving towards me.” Holden knows the feeling: “I felt it, too, every time we go through a Ring.” This implies a relationship between the gates and the Builder-killers. The dark sphere does resemble a gate or perhaps the entire Ring space, which is essentially “between things” itself. Because of this special experience, it might be that Elvi will be the only Ilus character appearing in future seasons of The Expanse since the rest of the Barbapiccola crew, including Lucia and her family, can use their lithium earnings to settle elsewhere.

Some other families, however, may not be so lucky. Naomi, for instance, wants Fred Johnson to help her get in touch with her long lost son, Filip, before Marco can make him an extremist, but she may be too late since the young man is standing at Marco’s side in the moments before Ashford is sent out an airlock. Ashford was able to send a recording of Marco’s boast to an OPA associate, but whether it’s enough to tip the Earthers off to the impending disaster remains to be seen. We’ll miss David Strathairn, but at least Naomi’s appeal to Johnson might mean we’ll get to see more of Chad L. Coleman in The Expanse season 5, which would be a suitable consolation.

It’s a good thing Drummer didn’t go with Ashford on his fateful trip. Her decision means that she may end up being in charge of Medina Station despite her desire to stay away from politics. Similarly, because Avasarala was called to Luna at the end of The Expanse season 4, this likely places her out of harm’s way if Marco’s stealth asteroids make it through Earth’s defenses, and she may end up retaining more power than she believes in the emergency situation. Her departure from Earth can’t be a coincidence, yet it’s hard not to worry for her husband, who did not accompany her.

There are a few other details floating about that garnered our attention that may be important later, not just in the finale but elsewhere in the season. For example, there was that call between Amos and the imprisoned Clarissa Mao, whose alias “Melba” leads him to call her by the nickname “Peaches.” We’ll be keeping an eye out for this important pair, which features prominently in the novels. Amos’ relationship with Chandra Wei in this season of The Expanse proves that romance isn’t in the cards for our lovable sociopath, but he still has plenty to offer a friend to whom he is unerringly loyal.

Obviously there are certain advantages to any article purporting to explain the deeper story if its author has read The Expanse novels; Bobbie Draper’s story on Mars was quite different from the books, for example, and entire characters were missing from the Ilus storyline. But the TV show has proven it has plenty of tricks up its sleeve even for those who think they know what’s going to happen. All we can do as viewers is take the clues we have been given and make our best predictions to occupy our time during the interminable hiatus before our favorite space sci-fi series returns.