WARNING: If you don't want to know what happened in this episode, don't read this photo recap!
The crew on the Rocinante note that the UNN and Martian fleets are headed for some kind of massive confrontation near Callisto. But while that's going on, they're going to try to sneak past and get to Io to deal with the protomolecule experiments. As Holden, Amos, Alex, Naomi, and Draper go over the plans, which include nuking the place if there are hybrids, we see an emotion-less Prax loading a gun.
Elsewhere, the Kittur Chennamma has made it back to the Martian fleet, finding the MCRN Hammurabi. Our old pal Ensign Sinopoli is brought to Admiral Kirino, and he catches her up on his rescue, the Rocinante, James Holden, Roberta Draper, Chrisjen Avasarala, the whole gang. Kirino is more than a little incredulous at Sinopili's star-studded company. He shows her the recording of Errinwright incriminating himself and says that Avasarala needs that recording to get to Admiral Souther aboard the Agatha King. Kirino doesn't believe this, but is intrigued by the Agatha King's course for Io. Whatever is there must be of utmost importance. So she sends Sinopoli on his way and changes course for Io.
Aboard the Agatha King, Admiral Nguyen is still winning friends and influencing people with his personable ways. He tersely informs the crew that they're abandoning the rendezvous at Callisto and continuing for Io. Nguyen is confident the Martians will follow them there, and they can have their fight. After Souther voices one objection too many, Nguyen strongly suggests he keep away from the bridge.
On the Roci, Avasarala comes clean to Holden about one thing: she can't allow them to nuke the protomolecule on Io. Pretty much just like Naomi said, Avasarala needs the protomolecule so that Earth can stand on equal footing with Mars and the Belt. Holden is darkly amused, but Avasarala is insistent in trying to get his support. "For the good of Earth, Mars, and the Belt."
Alex is checking the comms when he sees a message has arrived from his son, Melas. Despite his mom's anger, Melas isn't mad. He seems to idolize his "warrior" dad. He's planning to follow in his dad's footsteps when he gets older. Alex is relieved but also broken up.
Elsewhere, Amos and Prax get a little target practice in. Amos has been working to get Prax ready for battle, but it seems Amos's emotionally detached affect has rubbed off as well. Prax seems all too willing and able to kill people on Io (including hybrids), and Amos looks concerned that the loving, empathetic Prax they once knew isn't home right now.
On the Agatha King, Admiral Souther is cooling his heels with his top lieutenants, Shaffer and Mancuso, who have both had it with Nguyen's leadership, and most of all his secrecy. They float talk of a mutiny, which Souther appears to disapprove of. When he leaves and Nguyen's right hand man, Boyer, arrives, Shaffer and Mancuso needle the ever-loyal Boyer about his boss.
On Io, Jules-Pierre Mao and Dr. Strickland observe Katoa, who is now being kept inside a glass tube. The protomolecule has infused and transformed him, and he appears to be in pain. Mao tries to get information out of him, about how the protomolecule communicates with itself, but all he gets are vague references to "the work." Then the protomolecule surges inside Katoa, and he starts writhing in pain.
On the Agatha King, Mancuso receives the transmission from the Hammurabi, and he informs Shaffer in secret. She takes it to Souther, who watches the Errinwright tape. He needs to confirm its authenticity before they do anything, but he tells Shaffer to be prepared for whatever comes next.
Souther presses his way into where they're holding Cotyar and gets the details that confirm the authenticity of the recording. Cotyar, meanwhile, can't hide his joy that Avasarala made it out alive. Before the men can discuss next steps, though, Boyer and his men arrive to bust this meeting up. They take Souther to see Nguyen.
On the Roci, Holden and Naomi once again attempt to build a bridge past Naomi's actions with the protomolecule. This time, she tells Holden about her past: her relationship with an OPA insider, how she had a child with him, a boy named Philip. The man she loved took him away when she refused to do what he wanted. Desperate and broken, Naomi shut everything away and signed up for the Canterbury. When she thought of the Belters, in the wake of Eros, she imagined her son among them. Holden is moved. She apologizes for not talking to him and the crew first. "I'm never gonna like what you did," Holden tells her, "but I can't hate you for doing what you thought was right."
On Io, Strickland and Mao have sedated Katoa enough to ask him to explain what "the work" is. Katoa can only say "soon" before the protomolecule starts making him freak out. Mao and Strickland escape to safety as Katoa begins to crack the glass in his tube. Strickland orders an emergency sedation. The protomolecule has changed him too much to be able to communicate. But Mao knows that "the work" refers to some kind of alien plan. When its done with whatever it's doing on Venus, they need to know what will happen next. With Katoa now unresponsive, they need to create another conduit. Mao flinches when Strickland tells him the next best candidate is Mei Meng, but ultimately he orders Strickland to move forward.
On the Agatha King, Souther is brought before Nguyen, who relieves him of duty. Before he can have him consigned to quarters, the Hammurabi approaches. Meanwhile, on the Hammurabi, Admiral Kirino argues with her second-in-command over her desire to, in light of the Errinwright recording, talking things out with Souther on the Agatha King.
On the Agatha King, Nguyen can't understand why the Hammurabi isn't firing on them. Souther realizes it's testing their honor. Nguyen isn't buying it, saying there's no honor in defeat. Meanwhile, as the Hammurabi gets closer and closer into the Agatha's firing range, Kirino asks Sinopoli whether he trusted Avasarala or not. He remarks that she was mean at first (yeah, no kidding), but he liked her.
Nguyen prepares to fire, but Souther counters it, and before you know it, we've got a full-on mutiny on our hands! Souther's people get the upper hand, and Nguyen is ordered into custody. Souther then gets an open line to all ships — Earth and Mars — and announced that they are standing down and that he'll be transmitting proof that they're fighting an illegal war.
Nguyen sees that some of the UNN ships have broken off, and even when he gets on comms and orders the ships to fall in formation, not all do. He orders the Jimenez in particular to respond. When they don't, he orders a missile lock on the Jimenez. Some of the Agatha crew members refuse to comply, so Nguyen does it himself. When they don't respond, he blows the Jimenez out of the sky.
With the Jimenez destroyed, Mancuso makes a grab for one of the guns. In the ensuing shootout, Nguyen, Mancuso, and Shaffer are all shot, with Nguyen shooting Shaffer dead. Meanwile, from the Hammurabi, Kirino and her crew watch the UN ships firing on each other. Despite pressure to finish them off, she gets on MCRN comms and orders her ships to stand down and let the UNN take each other out. She next communicates to the UNN that any ships who stand down will not be fired upon. Nguyen looks like he has other plans.