Unlikely allies Joe Miller and the crew of the Rocinante led by Jim Holden uncover more about the conspiracy to release the protomolecule on Eros station.

With the help of Fred Johnson and the OPA, Miller, Holden and the crew stage a raid for information on the protomolecule. On Earth, Avasarala learns a truth about Fred Johnson.

The Rocinante chases an asteroid as it hurtles towards Earth.

Preparations for the Earth/Mars peace conference tighten the tension on Erringwright.

Bobbie becomes a political pawn in the struggle between Earth and Mars.

The Rocinante crew deals with the fallout over Naomi's betrayal while caught in the middle of the war between Earth and Mars while Avasarala and Bobbie hatch an escape plan.

The Rocinante answers an unexpected distress signal. Bobbie and Avasarala find themselves being hunted by a mysterious captor. UN Secretary-General Sorrento-Gillis brings in a colleague from his past to lend an ear during this crucial time of war.

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.

The Rocinante tends to wounded Martian soldiers in exchange for supplies. Avasarala struggles with how to disseminate a key piece of evidence despite being in hiding.

The final battle between Earth and Mars threatens the very future of humanity. A new monster is unleashed on Prospero Station. Anna receives the smoking gun she needs.