As Hurricane Irma approaches Saint Marie the islanders are battening down the hatches and taking cover the team are called to the murder of a young meteorologist, Leo Downs (Mathew Horne). The crime scene seems to have been staged to make Leo’s death appear like an accident caused in the hurricane. It emerges that the victim had told the university dean that he had something important to tell her, but was dead before he had the chance. Leo’s colleagues all have potential motives for the murder from his jilted girlfriend, Amber Collins (Jo Woodcock), ambitious rival Jennifer Cheung (Gemma Chan), jealous housemate Damon Ryan (Ben Batt) and Professor Adam King (Stephen Boxer) involved in a controversial scheme about off shore drilling. All have photographic data collected at the time of murder giving them alibis. A rubber duck at the scene, no evidence of Leo's work and the timed photographs are the only clues. During the investigation Poole and Camille are trapped together by the hurricane and Poole's heart to heart chat with Camille about his father provide another insight into the crime.