In Chapter 4, historian Jim tells Kate the story of a Magic Horn which can grant a kind of eternal life. The Horn is lost in battle.
The fabled Merlin finds the Horn, then loses it. Chapter 5 blends worlds of fantasy and reality as Jim tells why he is hopeful of finding the ship Resurreccion and the Horn on this expedition.
Kate talks to Terry, the sonic imaging technology specialist in Chapter 6. Respecting only science, he scorns Jim's romantic quest.
In Chapter 7, Kate finds Isabella, the marine biologist, much more sympathetic to the quest for the Horn. Isabella buys an odd fish from a villager and experiments on it.
In Chapter 8, Isabella's experiments show the fish's genetic makeup allows it to experience continual regeneration, giving it a kind of eternal life. The crew gets a glimpse of a remarkably preserved Resurreccion on Terry's sonar equipment, but the image mysteriously disappears. They decide to explore the area beneath the whirlpool in Isabella's submersible vehicle.