In the summer of 2024, as Paris prepares to host the World Triathlon Championships on the Seine for the first time, a chilling discovery rocks the city to its core. Sophia, a gifted scientist, is alerted by Mika, a passionate environmental activist, about the presence of a massive shark lurking beneath the river’s surface. Fearing the potential chaos and danger that could ensue, they enlist the help of Adil, the commanding officer of the Seine river police. Together, they embark on a high-stakes mission to confront this underwater menace and prevent a catastrophic event from unfolding in the heart of the city. As they delve deeper into the dark waters of the Seine, they must navigate through a web of mystery, suspense, and danger, where every decision could mean the difference between life and death.