With the Ring Gates now open to thousands of new planets, a blood-soaked gold rush begins, igniting new conflicts between Earth, Mars, and the Belt. Meanwhile, on one unexplored planet, the Rocinante crew gets caught in a violent clash between an Earth mining corporation and desperate Belter settlers as deadly, new threats from the protomolecule emerge.

As the Rocinante crew digs deeper into the search for Prax's missing daughter, the war between Earth and Mars turns deadly in ways the solar system has never seen. But a new threat in the outer reaches of the Belt could prove much more dangerous, threatening to test the very future of humanity.