The reviews for these two books were originally written in April of 2016.

Caliban’s War by James S.A. Corey (really Daniel Abraham and Ty Franck) picks up not altogether too long after the final, captivating events of Leviathan Wakes and it smoothly carries on with the story of the relatively near-future narrative that is The Expanse.
The absence of Miller from the story is made up for in large part by a Holden who has become more like the detective than he would have thought possible judging by how harshly he had criticised Miller’s methodology and personality during the first novel. This internally conflicted characteristic makes Holden a more interesting and substantial protagonist than he was in the first book though it does produce some difficulties on board the Rocinante.
Fans of the television show would be gratified to see Chrisjen Avasarala finally making her appearance in the literary version of The Expanse. Though she is more vulgar in the book than in SyFy’s adaptation, the core of the character is there…a ruthless and often cold political force to be reckoned with who manages to compartmentalize her personal and professional lives with impressive skill.
The new characters added into the narrative are well-developed and easily as interesting as those from the first novel, which is something I hope they can keep up through the additional books in this series (including the ones as yet unwritten).
It says something about the intense and dangerous nature of the events unfolding in this book that an alien biological machine terraforming Venus according to entirely unknown programming takes a backseat in the minds of the characters and that same dismissal carries over to the reader…at least until the end, when it can no longer be ignored.
I am very much looking forward to reading the next installment after the way this one ends and I am even more so looking forward to seeing how the television adaptation will tackle things as the events of this book make it onto the screen during either the latter portion of season two or the beginning of season three depending on how they put everything together.

Abaddon’s Gate takes The Expanse series through the first tentative steps toward becoming a full-fledged, interstellar space opera. From this point on in the series, humanity will no longer be confined to the solar system we’re all too familiar with and the surrounding void between our local system and other stars.
This is, surprisingly, the first time religion really gets brought into the books…and there is quite a bit of it, as well there should be. This is a series of novels that is largely predicated on first contact, and that would damn well shake up religious thought all over the world. Not only are we dealing with first contact, but first contact with an unknown species that was around billions of years before we came down from the trees and who have the ability to manipulate matter and energy in ways we have only ever imagined possible. We stumbled upon something truly alien to us, waiting out at the edges of our solar system and disastrously attempted to weaponize it because, of course we would…we’re notoriously short-sighted and impulsive when it comes to thinking up ways to kill one another in real life and the odds of that changing over the hundreds of years separating us from the fictional future of The Expanse are pretty slim…and if none of this had an impact on us as far as theology is concerned, these books would require far too much suspension of disbelief.
By the time Abaddon’s Gate starts off, there is a giant ring structure (assembled on Venus by an alien intelligence before lifting from that planet’s surface) between the orbits of Uranus and Neptune, looming there and just waiting for us to cross the threshold…and it stands to reason that Holden would be one of the first to cross over into somewhere truly awe inspiring in what it represents.
Along with the novelty of having a religious perspective tossed into the mix we get a whole new cast of characters to populate the narrative since Holden and the crew of the Rocinante are the only major ones carried over from the previous novels into this one…and none of them feel like throwaway bit parts, which is something the authors have excelled at so far through the series.
This third volume of the series answers a number of questions that have been collecting since the first novel, but it certainly adds just as many new ones that will hopefully be just as exciting to answer in reading what follows.