Returning to his hometown after a long absence, Martin Scarsden’s hope for a peaceful holiday with new partner Mandy Bond takes a U-Turn when his childhood friend Jasper Speight is found dead and the only witness and suspect is Mandy.

As Martin continues to explore the events surrounding Jasper’s murder, he and Mandy deal with the information that someone at Hummingbird Beach Retreat, possibly Jasper, spiked her drink and drugged her. When long ignored family members confront Martin about an old betrayal, exposing secrets from his past, Mandy begins to question both Martin and their relationship.

When a witness claims to have seen Mandy dispose of the knife that killed Jasper, Mandy faces murder charges. Martin continues to hunt for the true culprit, uncovering more darkness in Port Silver, but no murderer. Jasper's mother Densie holds a vigil for Jasper at Hummingbird Beach which ends in a mass poisoning, with Mandy one of the victims.

In the wake of the mass poisoning at Hummingbird Beach Retreat with Mandy in a critical condition, Martin reflects on his past actions and reconciles with Uncle Vern. With Vern's encouragement Martin's instincts are restored and he follows a lead that ultimately proves Mandy’s innocence and uncovers the Jasper's killer.