The Underloft. Tides of Tomorrow, #3

The Underloft Tides of Tomorrow Book Three by August MaeBeneath the drowned towers of Bristol, in pressurised chambers where every breath is borrowed from the sea, a different kind of survival has taken root. The Underloft speaks through action, not words. They judge by craft, not promises. And they remember everyone who comes to their threshold. Seren, Moss, Gull, and Wren have crossed unknown waters and navigated the politics of the Rooftops.
But the medicine Havenswell needs lies deeper still, in flooded pharmacies and collapsed hospitals, in places where the old world sleeps beneath fifty years of silence. To earn passage into the drowned places, they must prove their worth. To find what they seek, they must face dangers that have claimed divers before. And to make it home in time, they must outrun something building on the horizon, something none of them can control.
The pressure finds every crack. Every weakness. Every secret.  Some truths cannot stay hidden in the deep. The Underloft continues the Tides of Tomorrow series, a hopeful climate fiction series for readers who love Becky Chambers, Station Eleven, and City of Ember.