The Ruin by Dervla McTiernan

It's been twenty years since Cormac Reilly discovered the body of Hilaria Blake in her crumbling Georgian home. But he's never forgotten the two children she left behind...

When Aisling Conroy's boyfriend Jack is found in the freezing black waters of the river Corrib, the police tell her it was suicide. A surgical resident, she throws herself into study and work, trying to forget - until Jack's sister Maude shows up. Maude suspects foul play, and she is determined to prove it.

DI Cormac Reilly is the detective assigned with the re-investigation of an 'accidental' overdose twenty years ago - of Jack and Maude's drug- and alcohol-addled mother. Cormac is under increasing pressure to charge Maude for murder when his colleague Danny uncovers a piece of evidence that will change everything...

This unsettling crime debut draws us deep into the dark heart of Ireland and asks who will protect you when the authorities can't - or won't. Perfect for fans of Tana French and Jane Casey.

This book is part of the "Cormac Reilly" series.
Here are some other books from this series: