At a dark place in Edinburgh's heart, secrets refuse to lie dormant.

At Police Scotland HQ, Grace Macallan has pitched up in Counter Corruption. But the demons of her past are never far behind.

Meanwhile, Edinburgh's gangland is in turmoil.

As a new breed of upstarts challenges the old criminal order, their battle for territory causes serious havoc.

Into the war steps DI Janet Hadden.

Ambitious, hardbitten and addicted to risk-taking, she knows how to throw opponents off balance. But when she’s thwarted, Hadden seeks help from a notorious underworld fixer, a man who keeps secrets but always extracts a price.

Beset by violence and double-crossing, Grace is soon embroiled in a savage game of cat and mouse with colleagues and criminals alike.

With all sides driven by dark desires, theirs is an endgame that will take Grace down unless she holds her nerve.