The crew of the salvaged Martian gunship Rocinante, captained by James Holden. Over the course of nine novels, the crew - Naomi Nagata, Amos Burton, and Alex Kamal - expands to include Bobbie Draper and Clarissa Mao, and finds itself at the centre of nearly every major crisis in the solar system.

The military arm of the Martian Congressional Republic, one of the three great powers of the solar system. The MCRN is widely considered the most professional and technologically advanced military force in human space, maintained by a culture that views military service as both duty and honour.