The Expanse · Character
Captain Martens
Also known as Martens
- Supporting
- First seen · Book 2 · Ch. 4
Captain Martens is a supporting character in The Expanse (Book 2).
- Gender
- male
- First appears
- Book 2 · Ch. 4
- Books
- 1
Description
A human man wearing a Marine chaplain’s uniform of indeterminate religious affiliation. No physical features are described.
Connections
Family & partnersFriends & mentorsRivals

Roberta Draperconflicting source relationships
Martens is a Martian marine officer with training in psychology and theology who intervenes in Bobbie’s recovery. Their shared military background informs his attempt to reach her.
Story so far
BOOK 2Caliban's War
Appearances
Meet Captain Martens in Bookworm
Meet Captain Martens in your EPUB — spoiler-safe to the book you're on.