Julie's origin story ends up revealing her trajectory. Holden and Miller work together as they take a look at a strange emergency happening on Eros.

Miller devises a dangerous plan to eradicate what's left of the protomolecule on Eros.

Holden leads his crew through the war-torn station on Ganymede.

As Earth strategizes a costly ploy to gain advantage in the war against Mars, Anna struggles to convince Sorrento-Gillis to do the right thing. Avasarala and Bobbie seek refuge aboard the Rocinante.

Drummer and Ashford find themselves trapped with few options for survival; Anna tends to the wounded masses as Melba continues to hunt down her prey; the Rocinante crew struggles to survive as Naomi reunites with her true family.

New alien threats emerge on Ilus as Naomi battles health challenges on the planet. Bobbie searches for a missing person on Mars. Avasarala faces a new challenge in the UN.

Naomi and Alex work to keep the Barbapiccola in orbit amidst a power outage. Avasarala faces a tough decision. Holden and Elvi race to find a cure for a disease spreading on Ilus.

Avasarala faces fallout for the UN's military mission. Ashford and Drummer makes big decisions about their future within the OPA. A spreading illness on Ilus takes a toll on Amos. Alex and Naomi's attempt to rescue the Barb turns desperate.

Naomi comes face to face with Filip. Holden and Fred turn the tables. Avasarala closes in on Marco's plot.

Marco's grand plan shocks Earth, Mars and the Belt.

Naomi makes a desperate attempt to save her son from Marco. On the Roci, Holden battles for the last sample of protomolecule.

Amos returns to Baltimore with Clarissa. On Luna, Avasarala's alliances begin to shift. Alone and adrift, Naomi becomes a deadly lure.

Avasarala, with the Combined Fleet of Earth and Mars, takes the war to Marco. Filip and Marco's relationship is tested. The war becomes more perilous and personal for Holden and Naomi when the Rocinante is suddenly forced into a battle.

Holden finds himself at odds with his crew when a controversial decision is uncovered. On Ceres, Avasarala struggles to contain an escalating humanitarian crisis. Drummer's growing faction stage a daring raid with dire stakes. Filip, demoted to repair skiff duty, makes an unexpected discovery.