A Spanish factory near Barcelona is secretly producing--under the guise of a dumpling maker--a key machine for the production of nuclear weapons. Western intelligence has gotten wind of this and believes that the machine is meant for North Korea. It is deemed imperative either to disable the machine before it leaves the factory or intercept it. Inspector O is recruited by an old friend to take part in an operation to disrupt the plans for shipping the machine. The buyer of the machine has constructed an elaborate double-blind story, making it appear as if the purchaser is a Japanese criminal organization acting on behalf of the North Koreans.