Slonczewski was a working microbiologist and it changes the texture of the whole book, the Sharers of Shora don’t just live on their ocean moon, they’ve bioengineered themselves and their world down to the cellular level, purple-skinned, genderless in the story’s framing at points, capable of manipulating their own biochemistry with a precision that reads more like applied biology than magic. It’s genuinely rare to read invented biotech that feels like it comes from someone who’s spent real time at a bench, and that grounding is what keeps the more out-there worldbuilding, sentient rafts, engineered “silverfish” transport, from tipping into hand-wave.

The core of the book is the Sharers’ response to Valedon’s occupying force, and it’s not pacifism in the passive sense, it’s a coordinated, exhausting, deliberate refusal, absorbing violence without retaliating in kind while also never simply submitting, and Slonczewski does not romanticize how brutal that strategy actually is to live through. There’s a stretch where the occupying soldiers, trained their whole lives on hierarchy and threat, start to genuinely unravel at having no enemy to fight back against, and it’s one of the more unsettling depictions of power meeting a wall it doesn’t have a script for that I’ve read in genre fiction.

It’s slow in the middle, deliberately so I think, the pacing mirrors the Sharers’ own patience and that’s clearly the point but it does test you, and Spinel’s arc as the Valan boy adopted into Shora society takes longer to pay off than I wanted. Four stars, not five, purely on pacing, but the ideas are still knocking around in my head weeks later, which counts for more than a smooth read most of the time.