I'm going to cut to the chase: I detested this book. The Expanse at its best was a space mystery chasing down the fantastical proto-molecule. But it always had an undercurrent of violence-is-wrong and information-is-equality, and that philosophy rears its ugly head in Babylon's Ashes. There's incessant moralizing on the heels of Nemesis Games (spoilers incoming for the previous book), where state-sponsored terrorists killed ten billion civilians.

Half of human civilization is dead, and yet Belters are cheering for supervillainy that belongs in Marvel Comics, and declaring their support for the nation that stands on top of a war crime that makes the Nazis look restrained. Any wrongs, and I do mean any wrongs, pale in comparison to the deaths of ten billion civilians. And yet we're supposed to restrain and not retaliate? Sympathize and forgive these people? Be reminded that Belters are humans too?

Throughout the pages of Babylon's Ashes, the authors write as-if the attack on Earth was a Pearl Harbor. Belter narrators introduce the Free Navy, and we have to read about people who feel they've got the moral high ground because of the colonialist exploitation of Belters. Except they just killed ten billion civilians. And yet all our heroes twist themselves into knots to save Belters, despite them collaborating with a regime that is actively trying to exterminate them all!

Moving on: the Expanse is shifting into military science-fiction, and it fails miserably to deliver in that genre. The authors had always chosen to let the plot dictate what spaceships did, with the thinnest veener of hard sci-fi on top of it. The type of weapons, combat tactics, fleet makeup and locations... these were always fuzzy. Unfortunately, in military sci-fi, these things matter so that battles have impact.

In Babylon's Ashes, ships are destroyed in combat because the plot wants you to be worried, or more will magically appear because it'll be impactful. There's enough to take back territory until suddenly there isn't because overreach! They're always fast enough to ambush the protagonists, and slow enough so that there's no use chasing the antagonists. It's all amateur hour because either the authors never bothered doing the math, or didn't bother to plan so they could foreshadow correctly.

I know Persepolis Rising is more of the same, so I'm done with this series. It was a fun space fantasy adventure. It's terrible military sci-fi.

Not Recommended.