After reading the blurb for Floodline, I was worried I was in for something a little more lightweight than you’d expect from Kathryn Heyman: ‘The feisty, sexy and dynamic host of a Christian shopping channel’ sets out on a grand mercy mission to save the town of Horneville from ‘the gays’ after a terrible flood has destroyed the city.

But this book has real depth and soul. While the characters are diverse – and could have become chaotic in the hands of a less-skilled writer – under Heyman’s guidance they are full of heart, utterly three-dimensional and played completely straight.

Floodline uses a split narrative to pick through the wreckage wrought by epic disaster on ordinary lives. One disaster is smaller, more everyday, but is of course huge in the lives of the people it involves. A marriage betrayal – slowly teased out and laid bare to the reader as we get further into the book – laps at the feet of the family involved, threatening to drag them under unless they release the floodgates and let forgiveness and truth flow.

A parallel storyline examines the impact of a treacherous flood. Inspired by the real-life aftermath of Hurricane Katrina, and the Queensland floods a couple of years back, this story is seen from the perspective of a nurse involved in caring for patients at the major Horneville hospital. Generators have broken down; water has run out; medical supplies are dwindling; the heat is stifling; no one has slept for days; evacuation of particular patients seems impossible; and horrific decisions are made.

But in the end, this book is not just about struggling to keep your head above water: it’s also about hope and cleansing – and it’s a cracking good read.

Gabrielle Williams is a bookseller at Readings Malvern.