A direct sequel to Leviathan Wakes, Caliban’s War is book number two in The Expanse saga. It picks up about 6 to 12 months afterwards. Holden and crew are policing for the Outer Planets Alliance (OPA). Holden is hardening, losing his charm and his relationship with the crew and Naomi is suffering. Ganymede is the breadbasket of the belt, probably the most important strategic location in the belt and since the Eros Incident has been occupied by Mars and UN (Earth) military forces in an uncomfortable detente. An unknown alien super soldier sparks a shooting match between these forces leaving Gunnery Sergeant Roberta Draper (Bobbie) of the Martian Marines the sole survivor and witness in the close encounter. The book brings together four threads: Prax, Holden, Bobbie and Avasarala. Prax is a biologist and food expert on Ganymede. He is caught when the fighting breaks out and loses his young daughter to kidnappers. Avasarala is basically third in command at the UN. An old foul-mouthed lady and an expert in playing the political game. Bobbie is sent to the UN on Earth as the sole witness to the alien attack. Avasarala hires Bobbie and is convinced of her story, working hard to de-escalate a UN on the war path with Mars. Holden is directed by the OPA to Ganymede to assess the situation. Once there they encounter Prax and offer their help because Holden realizes that the kidnapped children are part of a deeper plot since they are conveniently taken just prior to the attack. They also encounter suspicious security forces and hidden medical facilities. Prax, Holden and crew depart Ganymede, survive a tangle with another alien super soldier who stowed away and head to OPA headquarters. Holden is convinced that his boss and OPA leader had something to do with the reemergence of the protomolecule since Holden had entrusted Fred with the only recovered sample. Holden is mistaken and Fred fires him. Without a patron, Holden has no means to supply his ship, so he makes a tell all video broadcast seeking help to find Prax’s daughter Mei. Through it they generate a lot of revenue via donations, enough for Prax the hire Holden and continue their search. Prax figures out that the kidnappers have absconded to Io so Holden and ship head there. They are pursued by a renegade UN combat force which itself is followed by a Martian combat armada.
Meanwhile Avasarala is ordered to Ganymede by her direct superior in an effort to isolate her while on-route. She brings Bobbie with her. While travelling the ship monitors her communications and impedes her progress until she eventually can legally commandeer the ship (with Bobbie’s assistance). Once in control of the ship they take a small racing ship from the shuttle bay and speed towards Holden in an effort to join him so that the renegade UN force will not fire upon him. However the shooting starts once everyone arrives to Io and the UN flagship becomes infected by the proto-molecule. Also about 200 super-soldier missiles are launched from Io towards Mars. They are impossible to track without their transponders so Holden boards the doomed UN flagship to successfully retrieve the codes. During this time, Amos, Bobbie and Prax successfully raid the secret base on Io to rescue Mei and the other missing children. The book wraps up with the renegade UN hawks vanquished, Avasarala promoted (since her superior was involved in the plot), Bobbie heading back to Mars, Prax reunited with his daughter heading up the reconstruction efforts on Ganymede and Holden and crew happily freelancing.
Caliban’s War is much the same as Leviathan Wakes. Pacing is excellent as it switches among the different storylines uniting them all near the end. However with an identical atmosphere as before it doesn’t have the same impact as Leviathan, though, the second book provides more politics through Avasarala better justifying its space opera subgenre. It provides another sinister adversary (like Protogen Security in the first book) in the form of renegade UN hawks who develop a human-protomolecule hybrid super soldier (from the abducted children who all suffer from some auto-immune condition) bent on using it against Mars. It continues to fold in more mysteries concerning the proto molecule and its activities on Venus (with the apparent instantaneous network communication between the aliens). This mystery culminates on the last page with Miller seemingly back from the dead but sustained by the alien wanting to talk to Holden. So the alien mystery grows.
Would I change anything? I kept hoping that Bobbie would join Holden’s crew as gunner. The sexual tension between Holden and Naomi is over now that they are a serious couple and Bobbie would add another variable, if not with Holden, then between Alex and Amos. Also, the book never tells you who “Caliban” is. Finally, the book didn’t leave me in a contemplative mood (what what-if sci-fi is so good at), though admittedly Caliban’s War isn’t that kind of book.
(Amazon) Caliban’s War