WARNING: If you don't want to know what happened in this episode, don't read this photo recap!
137 years ago, back when Mars was just a colony under UN control, an engineer named Solomon Epstein was tinkering with the jalopy of a space ship that he owned. Initially just trying to marginally improve fuel efficiency, Epstein hits the drive button and immediately begins traveling far faster than he ever imagined. Narrating the flashback, Epstein says his discovery changed everything.
Back in the present, the UN security council is grappling with what Eros has done. Colonel Janus thinks it was a test of a new Martian fuel drive, a notion that Avasarala scoffs at. Whatever it is, Janus says, Eros represents the "greatest technological leap since the Epstein drive." They plan to send a team to Venus to investigate.
Holden sends a message home to his mother, telling her he's okay and how proud he is of his crew (especially Naomi). Later, he and Naomi continue to debate over whether or not they should destroy their sample of the protomolecule.
Holden and Naomi stand in front of the rest of the Rocinante crew and make the big announcement that they're seeing each other. After a pregnant pause, Amos and Alex erupt into laughter and say that Alex lost the bet. Amos is surprisingly cool with all of this.
Alex then pulls Holden aside to point out that 30 of the nukes that Earth sent have not been shut down. Where are they now? Well, see that they've been caught by a giant space net. Guess whose net it is...
137 Years Ago: Epstein's fuel-burning breakthrough was great for makind but kind of terrible for him, as he's now speeding off into space at Gs that will surely kill him. He tries to reach the panel to turn off the burners but he can't.
Avasarala has dinner with Dr. Michael Iturbi, who was present at the earlier UN meeting. The two of them seem to have some kind of romantic history, but she shuts that down quickly. He's fascinated by what's happening with Eros, and his theory as to why it did what it did is essentially what actually happened, so he's on the ball. He asks Chrisjen to find a way to get him onto that transport to Venus. He offers to be her eyes and ears there if she does.
Holden and Naomi speak to Fred Johnson about the 30 missing nukes. Fred doesn't so much see it as a problem because he's got them. Holden thinks they ought to jettison the missiles and tell Earth and Mars about the protomolecule. Fred counters that the nukes can be good bargaining chips, and as for the protomolecule, the safest thing they can do is keep Earth and Mars in the dark.
Alex, enjoying his hero status, chats up a lady but runs afoul of her husband. This starts a brawl, but Amos shows up out of nowhere and beats the husband down. He's bunking at the brothel next door, see.
After Fred tells Holden that he's going to need to pick a side as things escalate, Naomi goes to see Fred as well. She thinks they should tell the people everything about what Miller and Julie did on Eros. Not the protomolecule stuff; just how an Earther/OPA member and a Belter came together to save humanity. That story has value. Fred agrees.
Later, the Roci crew debates whether they should destroy their protomolecule sample. Alex says they should give it to Mars, which earns him a heap of side-eye from Belter Naomi. Ultimately, Naomi drops her objections and agrees with Holden and Amos that they should kill it.
137 Years Ago: Epstein is about to die - of a stroke, most likely. But he voices over about his discovery and how it would allow Mars to finally break free of its colonial limitations, travel out into space, mine the asteroids, and colonize the belt.
Avasarala finally confronts Errinwright about his working with Mao. She says they need to know what Mao knows and cut a deal with him. Avasarala goes OFF on Errinwright, saying that she will threaten to ruin Mao's family if they don't bring him forward.
On the Roci, Alex comes upon Amos defacing the Martian flag (erasing Deimos since it's not there anymore) and starts beef with him. He's still mad about the bar fight and Amos treating him like some damsel in distress. Amos matter-of-factly says he does see Alex as weak and in need of protection. Alex, as you might imagine, objects to that assessment.
On the shared US/MCR station of Ganymeade, Bobbie Draper and her marines patrol the border zone. While in a communication blackout, they spot gunfire on the UN border line. Suddenly, the marines' comms are jammed, and six marines appear to be charging at them. But as Bobbie sees, something seems to be...chasing the UN marines.