A detective from Ceres who works for Star Helix, characterized by his pragmatic and somewhat cynical demeanor. His investigation into a missing person's case becomes pivotal to the unfolding events.

A highly skilled Belter engineer on the Canterbury, known for her intelligence and ability to inspire loyalty. She plays a crucial role in helping her crewmates, particularly Holden, adapt to changing circumstances.

A mechanic on the Canterbury who is originally from Earth, notable for his strength, humor, and fierce loyalty to those he trusts. He has a mysterious past that influences his perspective on morality and violence.

A former Martian Navy pilot who joins the crew on their mission, known for his exceptional flying skills. His love for flying sometimes overshadows other aspects of his life.

An Earther who becomes an OPA activist and plays a critical albeit indirect role in the story's central conflict. Her story motivates characters, particularly Miller, in their quests.