A single spark can start a blaze. DS Catherine Bishop's life was thrown into turmoil by one of the most brutal cases of her career, and she is still dealing with the aftermath. But her own trauma must be put aside when she is called to a horrific scene of domestic violence - and murder. The investigation brings intense scrutiny for a police department already overwhelmed by the crimes of an arsonist hellbent on destruction. And as Catherine learns about the victims, it leads to more questions than answers. By the time the puzzle pieces fall into place, Catherine will once more have come dangerously close to risking everything. Does she still have what it takes to bring a killer to justice - or will her demons prove the ruin of Catherine after all?