James Holden
Idealistic executive officer of the ice hauler Canterbury, who survives its destruction and ends up captaining a captured Martian corvette he renames the Rocinante. His broadcast pinning the attack on Martian Navy hardware touches off a three-way war, and he later helps buy Miller the time to turn Eros aside while refusing to surrender the protomolecule sample to anyone.
Joe Miller
A burned-out Belter detective on Ceres handed the off-the-books job of finding the heiress Julie Mao, a case that becomes an obsession and costs him his career. He executes Dresden on Thoth Station, stays behind on Eros by choice, and finally persuades Julie to steer the transformed station into Venus as his own body fuses into the wall at her side.
Juliette Andromeda Mao
A wealthy racing pilot and activist heiress who threw in with the OPA against her Earth family, and who was infected by the alien protomolecule aboard the Anubis. Her body dies on Eros, but her consciousness ends up driving the transformed station, and Miller persuades her to veer toward Venus instead of home.
Naomi Nagata
The Canterbury's Belter engineer, who becomes Holden's second aboard the Rocinante and, eventually, his lover. She ignores the order to leave him behind on Eros, gets into Julie's terminal, and reworks the Belt's transponder network into a decoy scheme that delays Earth's nuclear launch.
Amos Burton
The crew's Earther mechanic, whose leg is shattered during the escape from the Donnager. He is waiting at the Eros airlock with rifles when Holden and Miller stagger out, and he locks the Rocinante down when Fred Johnson demands custody of the sample.
Alex Kamal
The Martian pilot who burns the survivors clear of the Donnager as it self-destructs. He goes on to fly the Rocinante through the fight at Thoth Station and the pursuit of Eros, slipping a UN corvette's fire without shooting back.
Fred Johnson
An OPA leader on Tycho Station, still infamous on Earth as the Butcher of Anderson Station. He shelters the Rocinante crew, directs the assault on Thoth and the Nauvoo ramming plan, and closes the book quietly holding humanity's only protomolecule sample as he opens a peace conference on Ceres.
Antony Dresden
The Protogen executive who ran the Eros experiment and helped engineer the interplanetary war as cover for it. Captured at Thoth, he calmly defends sacrificing a station full of people as the price of catching up to the protomolecule's makers, and Miller shoots him dead mid-argument.
Captain Shaddid
Miller's boss at Star Helix on Ceres, who quietly assigns him the Julie Mao case and later, openly working with Dawes, strips him of it and fires him as the OPA takes over the station.
Anderson Dawes
The OPA's liaison on Ceres, who alternates between pressuring Miller to drop the Mao investigation and feeding him evidence, including proof of who smuggled out the station's missing riot gear.
Havelock
Miller's Earther partner on the Ceres force, later employed in private security at Protogen. Miller leans on the old connection to pry loose the location of Thoth Station.
Shed Garvey
The Canterbury's medic and one of the handful who survive its destruction aboard the shuttle Knight, until a round through the Donnager's hull kills him in front of his crewmates.