DI Humphrey Goodman and his team face a perplexing case in the fifth season of "Death in Paradise" when millionaire environmentalist Dan Hagen is found shot dead on his boat while sailing near the idyllic Saint Marie. The investigation begins with limited clues, as the crime scene offers no immediate leads. Hagen, a prominent scientist and philanthropist, had no obvious enemies, leaving the team to delve into his personal and professional life for motives. The absence of witnesses and the remote location of the murder further complicate the case, forcing Goodman to rely on his unconventional methods to piece together the puzzle.   As the team interviews Hagen’s associates, they uncover a web of secrets, including disputes over his latest eco-friendly project and tensions within his inner circle. Suspicion falls on his business partner, ex-wife, and a local activist, each with their own reasons for wanting Hagen dead. Goodman’s keen eye for detail leads him to a crucial piece of evidence—a discrepancy in the boat’s logbook—that points to a carefully planned murder rather than a random act of violence. The team must navigate through red herrings and hidden agendas to uncover the truth.   The case takes a dramatic turn when a second body is discovered, linking the murders to a broader conspiracy. Goodman’s quirky yet brilliant deductive skills ultimately reveal the killer’s identity, exposing a shocking betrayal. The season opener sets the tone for another series of intricate mysteries, blending humor, suspense, and the stunning Caribbean backdrop that fans of "Death in Paradise" have come to love.