There is the decoding office of the Japanese Branch of Unicorn Organization in the basement of a lighthouse on the coast of the Pacific Ocean. One night, the lighthouse is attacked by a monster that has come out of the sea and all the members are killed. Receiving an SOS, Daisaku (Johnny Sokko) and Minami rush to the scene. The building has become a ruin and the decoding machine is gone. It is serious, for if it falls in the hands of BF members, the secret places of Unicorn branches all over the world will be found out. They don't know that Spider and his men are hiding with the machine in a cargo boat on a nearby pier.