In the outer solar system near Saturn, James Holden and the crew of the ice-freighter Canterbury, investigate a distress call from a mysterious derelict ship, the Scopuli. On Ceres Station, Detective Miller begins an off the book investigation of a missing heiress, Julie Mao.

Holden and the crew are taken prisoner by the Martian Congressional Republic Navy. Miller deals with unhappy rioters. Avasarala plays politics and gets severely burned.

Holden and crew find themselves in the middle of a desperate battle while still aboard the Martian battleship. Miller’s partner, Havelock, goes missing.

Avasarala uncovers a game-changing secret while the future of the human race might be in Holden and Miller's hands.

The Rocinante chases an asteroid as it hurtles towards Earth.

In the thrilling season finale, Inners and Belters fight side by side with the crew of the Rocinante in a last, massive, desperate battle with Marco and his Free Navy, with the fate of the Solar System, the Ring Gates, and of all humanity hanging in the balance.