Former Met police officer Jodie ‘Nosey’ Parker is working a trial period as an auxiliary Detective Sergeant with the Penstowan police force. But living and working alongside DCI Nathan Withers – while still trying to grow her catering company – brings its own challenges, especially when Jodie’s attention is quickly taken up by the suspicious drowning of a local fisherman.

While tourists and locals alike are falling under the spell of the annual mermaid festival with its captivating legends of Sirens luring fishermen to their deaths, Jodie and Nathan fear they may have found themselves in the middle of a very real – and very dangerous – turf war. As the casualties start to stack up, they must face the likelihood that something sinister has been going on under their noses for some time…