I finished “Babylon’s Ashes” by James S. A. Corey last night and have had a thought about the structure of the series. The Expanse series has been set to end in three more books for a total of nine, which are collectively the Expanse Series. To my mind though, I am seeing a structure of a trilogy of trilogy. The first three books (Leviathan Wakes, Caliban’s War, Abaddon’s Gate) deal primarily with the chaos created by testing and using the proto-molecule, eventually finding out the true purpose of the alien material.
The current three books (Cibola Burn, Nemesis Games, Babylon’s Ashes) that I just finished deal with the true fall out of the century old injustices that have created the sociopolitical environment at the beginning of the series. The two major powers have gotten distracted by the crisis created when the proto-molecule was released on a large scale, leaving themselves open for attack by forces previously held in check. In addition, during their quest to understand and fight the crisis, they blindly stomped across the solar system without a care for the third party, the most wounded, Belters. Their arrogance will cost them greatly by the end of the second trilogy.
I have not read Persepolis Rising but my thought and hope is that the last three books will fulfill the plot line raised in the first three books. Early on, the writers outlined an alien race of supreme intelligence that found itself battling an unknown enemy wiping out entire solar systems. By opening the gateways created by the proto-molecule, humans have reopened the galaxy to whatever destroyed the makers of the proto-molecule. The final three books (Persepolis Rising, Tiamat’s Wrath, Unnamed book),or final trilogy in my mind, should finish this over-arcing plot and bring the series to a conclusion. Let me know what you think.