The Expanse Season 5 Finale Ending Explained
Contains spoilers for The Expanse, through the season 5 finale
After plenty of political maneuvering, intense space battles, catastrophic terrorist attacks, and exhilarating espionage, Amazon Prime Video's The Expanse wrapped up its fifth season on February 2, 2021. Following the finale of The Expanse season 4, Belter insurgent Marco Inaros (Keon Alexander) makes his presence known to the solar system, thanks in part to a secretive web of alliances. With the crew of the Rocinante split up, they are each forced to contend with these new challenges on their own.
Heading into the season 5 finale, each Rocinante crew member was in a precarious position. Naomi Nagata (Dominique Tipper) had been pushing her body to its breaking point, attempting to set up communications on the booby-trapped ship she found herself stranded on following her escape from Inaros. Meanwhile, Alex Kamal (Cas Anvar) and James Holden (Steven Strait) were coordinating an effort to save her — even though doing so put them directly in the path of Inaros and a reluctant Camina Drummer (Cara Gee), whose crew and ship he'd commandeered. And Amos Burton (Wes Chatham) had just fled an Earth ravaged by Inaros' asteroid attack in a stolen shuttle headed for Luna, where Chrisjen Avasarala (Shohreh Aghdashloo) had just been appointed UN Secretary General.
Here's how season 5 of The Expanse came to an end.
Camina Drummer's mutiny helps turn the tide of war
Headstrong Belter Camina Drummer emerged as a pivotal player in The Expanse season 5, and in the finale, she demonstrates just how little regard she has for carrying out orders delivered via threat. Inaros orders her to destroy the Roci, but as Holden's ship barrels toward the Free Navy, Drummer orchestrates a mutiny. She attacks Karal (Oluniké Adeliyi) — one of Inaros' most loyal foot soldiers whom he plants on Drummer's ship to make sure she's following orders — and prevents the Roci from being overwhelmed by Belter fire. In doing so, Drummer both takes a personal stand against someone she sees as a bully and gets revenge for Inaros' murder of her former comrade Klaes Ashford (David Strathairn).
However, her mutiny doesn't come without a cost. Serge Kylo (Wilex Ly), who is sent to Inaros' ship to ensure Drummer's compliance, is sent out of an airlock in response to her actions. She and her crew watch the punishment with tears in their eyes, but although Drummer is saddened by his death, she declares, "There was no other way. At least now, we can choose our own path."
Some of her crew take this to heart, and decide to leave Drummer's ship. But even though her decision cost her members of her crew, it's clear that for Drummer, standing up to Inaros and not being forced to take up his war was deeply important.
Naomi Nagata makes a leap of faith
With Holden and the Rocinante crew dealing with Inaros, Alex and Bobbie Draper (Frankie Adams) race to respond to Naomi's distress signals coming from the Chetzemoka. Although Naomi manages to attract the attention of her allies, she still isn't able to fix the system on the derelict ship enough to send a clear message letting them know that the Chetzemoka is actually a trap rigged with proximity mines meant to blow up anybody who comes to her rescue.
Knowing that Alex and Bobbie are speeding toward her, Naomi has to take yet another major risk to ensure that they are able to survive the ordeal. She puts on her mostly busted space suit and makes the leap into the void, hoping that Alex will see her floating before her very limited oxygen supply runs empty.
Just as it seems like Naomi might finally run out of luck, Bobbie intercepts Naomi and hooks her up to an oxygen unit. Sadly, Naomi's relief at finally reaching the end of her ordeal with Inaros is short-lived. When Bobbie calls back to Alex on the ship, she gets nothing but dead air. That's because Alex suffered a stroke and died — the result of the hard burn they used to evade the Belter navy and reach Naomi in time.
The remaining Rocinante crew reunites with Avasarala on Luna
After dealing a serious blow to Inaros' war efforts, the Roci heads to Luna, where Holden and Naomi have a bittersweet reunion with Amos. There's a sad acknowledgement that the Roci is now down to three original crew members, and then Amos pulls a clever guilt trip on Holden as he introduces him to the newest member of the team: Claire, aka Peaches (Nadine Nicole), who needs somewhere to go after Amos busted her out of prison back on Earth.
Everybody then gathers at a bar to celebrate their victories. Avasarala tells the assembled parties that the crew of the Roci — made up of Belters, Earthers, and Martians — working together is what Inaros hates, and that in order to beat him, she wants there to be more cooperation between the factions.
When Inaros initially attacked the Inner planets and broadcasted a message to the solar system in which he decried the abusive treatment the Belters have suffered at the hands of the Inners, it was hard to not have some amount of empathy. However, as we learned more about his personal life throughout The Expanse season 5, it became clear that while he may have presented himself as fighting for the underdogs, Inaros is a bully. He may claim to have the Belters' best interest at heart, but his extreme actions — combined with how we saw him treat Naomi and their son, Filip (Jasai Chase Owens) — make it clear that he's more interested in using the Belters' legitimate grievances in his own personal quest to gain power.
Avasarala, who advocated against taking extreme punitive actions against Belters in the wake of Inaros' attacks, clearly understands this. She knows that the way to beat Inaros isn't through force, but through diplomacy.
The shocking development that has huge implications for season 6 of The Expanse
The celebrations on Luna are cut short by another Inaros attack — this one on the Ring, the portal to other solar systems that was opened by the protomolecule at the end of The Expanse season 3. The same Martian military ships Alex and Bobbie were tracking earlier in season 5, which are being piloted by high-ranking members of the planet's military, appear to be allied with Inaros in the attack. Holden speculates that the only way Inaros could have bribed the Martians to join up with him is using a sample of the protomolecule, which he learned earlier in the season had fallen into Inaros' hands.
When Avasarala asks why the Martians would want to travel through the Ring with the protomolecule considering the chaos the alien technology caused on the recently colonized planet Ilus in season 4, Holden replies, "Maybe they know something we don't."
Through a transmission, we see that the Martians have indeed discovered another planet like Ilus called Laconia, where the protomolecule activates some massive, ancient alien technology. As Martian Admiral Sauveterre (Tim DeKay) and his ship cross the Ring gate to meet their comrades on Laconia, the ship appears to be erased by some kind of light.
Exactly what happened to Admiral Sauveterre's ship, what the Martians are planning with the protomolecule on Laconia, and how their alliance with Inaros will affect the rest of the Sol system are all huge questions that we'll presumably get answers to in The Exapnse's sixth and final (or perhaps not...) season.