For the last ten years, an incongruous war has been waged in the Gulf of Morbihan off the Brittany coast. In the late eighties, two businessmen had imported a new, more resilient variety of clams, one of the most expensive shellfish on the market, from Japan. However, the technique was flawed, the tanks leaked and the new strain developed wherever the current took it. A treasure hunt ensued in the area. Some specialised on the sea bed, others undertook to exploit this unexpected harvest using dragnets on the surface, equipped with protective clothing, boots and computers. Ten years after their escape, the Japanese clams are threatened with extinction, which may well be the only thing that can bring surface and deep-water fishermen together.