DI Shona Oliver’s fellow officer PC Hayley Cameron drowns during a triathlon in the Solway Firth. The post-mortem reveals drugs in Hayley's system, perhaps self-administered performance enhancers. But a puncture wound in the back of her wetsuit suggests foul play.

Shona and her colleagues investigate, but those closest to Hayley grapple with the truth and risk letting personal feelings cloud their judgement. Could the answers to Hayley’s death lie within Shona’s own ranks?

As the case hits the buffers, Shona clashes with her daughter and also faces difficult questions about the murder of her old boss. Will Shona keep her head above the water long enough to see justice done, and what will it cost her if she does?

The latest thrilling instalment in the unputdownable police procedural series by Lynne McEwan. Perfect for fans of Val McDermid, Ann Cleeves and Neil Lancaster.