Caliban’s War is the second book in the Expanse series. In this book, some of the protomolecule is found outside of Venus. Holden accuses Fred of releasing it since he has the only known piece. This gets him fired, so he went free-lance. After contracting with Prax to find his daughter he finds himself pulled into a political struggle.
This book introduces Sgt. Roberta “Bobbie” Draker, a gunnery sergeant in the Martian marines, Avasarala, a senior politician with the UN, and Prax, a botanist from Ganymede.
Although Bobbie appeared in the last book, she becomes a major character in this volume. Her viewpoint provides a quick threat analysis of situations and creates an unstated threat to other characters.
Avasarala has a strong personality and provides an excellent political backstory to large-scale events taking place. This gives the storyline a lot of complexity. She hires Bobbie as a bodyguard and general aide. This creates tension for Bobbie, who now has allegiance to opposing sides in the war, Earth and Mars.
Prax provides a focus for the crew of the Rocinante to find his daughter. Being an expert biologist, he reveals that Ganymede’s environmental system is collapsing and that the people there cannot survive.
Through the book, the threat of Venus keeps turning up. The reader is reminded periodically that something is going on and that threat is increasing. The end of the book is a cliff-hanger with events taking place on Venus.
The relationship between Holden and Noami evolves threatening the crew of the Rocinante since Noami is a critical engineer for the crew that cannot be replaced. She also ups the tension between Holden and Fred Johnson, bringing it to a peak when Holden confronts Fred on the issue of the protomolecule.
The book is well-written. I found the narration good and fitting to the respective characters. It is very easy and pleasurable to read.