Cibola Burn is James S.A. Corey's fourth outing in the Expanse series. Its intense action is set in motion by one compelling truth: humanity may be able to escape from our home system, but we have a lot of baggage that we carry with us.


Shortly after the first Expanse novel Leviathan Wakes was published, Orbit announced that the series would be extended for another three books. The enormous sandbox of Corey's solar system certainly lends itself to further adventures of the Rosinante and its crew, and by the end of Abaddon's Gate, access to the rest of the galaxy had been opened up to humanity. That's where we begin in Cibola Burn.


Warning: Some spoilers for Abaddon's Gate and Cibola Burn.

When Abaddon's Gate left off last year, the entire system was focused on the Ring, a massive structure constructed by the protomolocule. The ring opened up an entire network to humanity and thousands of habitable worlds which could be colonized. Quickly, refugees from the battle on Ganymede made the decision to jump through before anyone on the station can stop them. Once through, the Belters are now on the new frontier on Ilus, or New Terra.

Meanwhile, one of Earth's megacorporations, Royal Charter Energy, jumps to harvest the world's rich potential, chartering the planet and sending along their own science and security team to lay a proper claim to the planet. As they land, a band of extremist Belters blow up the landing pad, taking an entire science team and bureaucratic contingent along with it which sets the settlers and security forces against one another.

To defuse the situation, Captain Jim Holden and the crew of the Rosinante are sent at the request of OPA leader Fred Johnson and UN Assistant Undersecretary Chrisjen Avasarala to help ostensibly mediate the situation, amidst greater political ties that place them in an impossible situation. On the ground, Holden and Amos find themselves trying to keep the RCE Security from forcibly removing the colonists from the planet. RCE security, led by Murtey, is backed by the charter for RCE, are ready to enforce their claim on the planet. On the other side, the Belter colonists are ready to defend their foothold on Ilus. As the human drama begins to play out, the alien technology that covers the planet begins to activate, and a catastrophic accident on the planet threatens everyone in the system.


Cibola Burn is an outstanding addition to the Expanse universe, but I can't help but think that following the arc of Leviathan Wakes, Caliban's War and Abaddon'sGate, the author team behind James S.A. Corey (Daniel Abraham and Ty Franck) were left with a lot of options for the next couple of books. As a result, their latest outing is split between several major storylines, all of which support the novel nicely, but feel a bit scattered between the major arcs.


On one hand, Corey presents a careful look at the racism that has underlined most of the novels so far in the series. Along with physiological differences between Earthers, Martians or Belters, there's an undercurrent of racism between each group, and here, it comes to a head, with an Earth-based security team facing down a Belter colony. The message is implicit here: humanity will bring some of its worst traits far into the future, where differences will fester when there's someone who's slightly different, whether it be in skin color, upbringing or language.

Corey plays this out with no clear angles: the Belters have sought out a new home where they wouldn't have to worry about a hole in the side of their station or spacecraft; a place with air over their heads, and a real opportunity to live in a gravity well, and when that's threatened, they go to extreme measures to protect themselves. On the other side, the RCE and its personnel are focused their mission to survey the planet, and enforce their charter. It's a complicated situation with no clear good or bad. The absence of black and white makes it easy for Corey to address the range of complicated issues in a frank and realistic manner, which makes this book and its predecessors interesting to read over and over.


Corey shifts, largely for the first time, much of the action to the surface of a planet, outside of the spacecraft in which most of the story has already played out. It's a nice change of pace, and it's outstanding to see the pair flex their world building muscles with the world of Ilus. It's an interesting world, with enough detail to linger with as we explore alien ruins and artifacts, as well, as some of the specific elements which hint at greater things to come in the series.

This drama plays out planet-side and in the space above: Murtey and his team on the planet face down a terrorist threat against their mission, while Dimitri Havelock (Miller's former partner), works security on the Edward Israel, where he forms a small, ship-wide militia in the event that things go south. South they go, as the Belter ship in orbit, the Barbiapiccola, the Edward Israel and the Rocinante fall into a sort of hostile dance as events unfold below.


The other major storyline brings to light some new insight into the gate builders. Miller, perpetually in Holden's head (and, as we learn, isn't a real hallucination), guides the Captain along as the planet begins to wake up. The RCE scientists are there to examine the long-dead remains on the planet and the installations in orbit. Alongside the human drama that's playing out, Corey drops some dark hints at the larger picture. The gate builders are long-gone, and there's something on planet that's seriously messing with the remaining technology, something darker and menacing. The power that's at the disposal of the gate builders is astounding: as we saw in Abaddon's Gate, they've got some pretty incredible tools at their disposal and it's been a building thread since we were first introduced to the protomolocule in LeviathanWakes.

While the two threads have played out in all the books, this one feels a little more scattered with the crew of the Rosinante split up between planet-side and orbit, and with characters representing quite a few angles. After the first 'trilogy' of stories, there's a whole new world out there, and the possibilities are enormous for the team, and it'll be interesting to see in just what direction they'll take the next two volumes.


Cibola Burn comes at a point where discussions of civil rights are in the forefront of our attention, and Corey shines a light on similar themes. Racism, bigotry and aggressive nationalism follow us to the stars in the Expanse, and in such a hostile environment, the stakes are high, and the means are far from clear cut. Alongside the action and excitement of a space adventure, they populate the narrative with some deeper points that give and have given the Expanse a depth that makes this series stand out. In any other hands, a comparable book would fall apart, but Corey makes this all look effortless.

While Cibola Burn feels a bit scattered, it's setting up another major arc in the series. From the foreshadowing that we've seen here, we're in for an incredible couple of novels. The Expanse is the best space opera series running at full tilt right now, and Cibola Burn continues that streak of excellence.