Surface Tension gives another example of a culture of adapted humans: A pantropy starship crashes on an ocean world, Hydrot, which is on orbit around Tau Ceti. With no hope for rescue, the few survivors modify their own genetic material to seed microscopic aquatic "humans" into the lakes and puddles of the world and leave them a message engraved on equally scaled metal plates. The story then tells how over many seasons, the adapted human newcomers explore their aquatic environment, make alliances, invent tools, fight wars with hostile beings and finally gain dominance over the sentient beings of their world. They develop new technologies and manage to decipher some of the message on the metal plates. Finally they build a wooden "space ship" (which turns out to be two inches long) to overcome the surface tension and travel to "other worlds"—the next puddle—in search of their ancestry, as they have come to realize that they are not native to their world.