Conan gets cornered on a ship where the past literally sinks back up to haunt everyone aboard. The mystery collapses into a two-suspect standoff that feels thin for the franchise, but the claustrophobia holds, water rising, nowhere left to run, and a killer who knows exactly how to use that. What saves it is the action: Conan and the crew fighting not just for the truth, but for their lives while the ship dies around them again.
A luxury liner cuts across the Pacific Ocean on its maiden voyage, carrying Conan and his companions among wealthy passengers and mysterious strangers. What begins as a glamorous getaway quickly unravels when a passenger dies under suspicious circumstances, trapping everyone aboard with a killer. Conan recognizes the threads connecting this crime to a maritime disaster from fifteen years ago. A sunken cargo ship, a dead ship designer, and a chain of deaths orchestrated with calculated precision all point toward someone seeking revenge. With no escape and nowhere to hide on the open water, Conan must piece together the conspiracy before the killer claims another victim. The ocean becomes a pressure cooker of secrets and resentment. Other passengers harbor their own hidden connections to the past, making it impossible to trust anyone. Conan races against time to expose the truth behind both crimes, knowing that every moment matters when you're stranded at sea with a killer who has nothing left to lose.