In this chapter, the ghost of the human algoritmo is revealed to be Hirohikawa, the mysterious man who has been haunting the city of Osaki. The ghost is a human being who is part of the city's human psyche, and he is the source of the mystery surrounding the disappearance of Atsuko and her companions. The man is Hiroyuki, the protagonist of the story, who rides a turtle into the sea and befriends a princess of a dragon palace. The princess is kidnapped from the inside of the ship by a remote maintenance system, and the two of them have been keeping an eye on the sea. They have heard stories that a valuable cargo was on board the ship, and they are planning to get close enough to the treasure to be able to find it. Hiroyuki hints that they will need to keep the turtle's tail around in order to catch the eye of the dragon princess, who is looking for the ship. He also hints that the turtle has been caught in the water, and that it is time for Hiroyuki to find out the riddle.