Return to the beautiful city of Bath as DCI McDonald (Tala Gouveia) and DS Dodds (Jason Watkins) face some of their most challenging investigations yet in three compelling new crime stories. McDonald, a tough, ambitious Londoner with a sharp wit and a no-nonsense approach to policing, and Dodds, a shy, unassuming local detective whose bumbling nature conceals a keen mind, couldn't be more different. But much to everyone's surprise, this mismatched pair are proving to be highly effective at cracking complex cases of murder and intrigue in the seemingly sleepy Avon Valley. In Season Four, McDonald and Dodds unravel the case of a woman who has been missing for decades, are sucked into a mystery involving a priceless artefact and the birth of the Blues, and find themselves in a desperate race against time as a spate of murders plague weddings across the city.