During a torrential rainstorm out at sea, two brothers are hanging on desperately in their rowboat as it suddenly capsizes from the waves. The two make their way to a small home and ask the owner if they can stay there for the night to brave the storm. The owner lets them in and suggests that they should change into dry clothes, then goes to find them some from a dresser. As the two begin to undress, a gun drops from the waist of one of them, who quickly hides it in a basket. As the home owner invites them to sit for tea, one of the brothers asks him if he knows of any good divers, to which he replies that he is one. The two tell him that they'll talk more about what they'd like him to fetch from the ocean tomorrow. The next day, the three make their way out to where they want him to dive, informing him that it's a suitcase that he is looking for. As he makes his way down towards the suitcase, he sees Agon resting near it, and immediately swims back towards the surface. He tells the two that he saw a monster that he is certain was Agon, and that the suitcase was right at its foot. As he tells them that he must go to inform his neighbors, the elder brother insists that he keep things quiet until he salvages their suitcase once Agon leaves, and threatens him with his gun that he do what they ask. Goro and Satsuki are out fishing when Monta arrives and tells them that it's a terrible place to fish, and goes home to get his fishing rod. When there, he finds his father and the two brothers; the younger one taking him hostage so that his father doesn't try to escape or alert the police. The three go out to the salvage area again, but with Agon still resting in the area, Monta's father is unable to retrieve the suitcase. The two brothers decide that moving Agon would be the only way to salvage the suitcase, and the elder brother suggests using uranium to lure him away, stealing some from the Fuel Laboratory. That night, the two of them make their way into the