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.

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…

A discovery pushes Naomi and Holden apart and sets the Rocinante crew against each other.