Martian marine gunnery sergeant who witnesses something on Ganymede that her government wants buried. One of the most physically formidable characters in the series, she is also one of its most principled - a soldier who cannot stop asking whether the orders she follows are worth following.

A high-ranking Martian military officer with a long-term strategic vision. A calculating and patient leader who positions himself to shape humanity's future beyond the Sol system.

A Laconian naval officer and commanding officer of the Barkeith. A career military man loyal to the Laconian cause during its early expansion beyond the Sol system.