By Larry Niven
Sequel to The Integral Trees
First, a note about the "world" of the Smoke Ring. This is from Wikipedia, since it explains it much better than I could ever hope to.
"The story occurs around the fictional neutron star Levoy's Star (abbreviated "Voy"). The gas giant Goldblatt's World (abbreviated "Gold") orbits this star just outside its Roche limit and therefore its gravity is insufficient to keep its atmosphere, which is pulled loose into an independent orbit around Voy and forms a ring that is known as a gas torus. The gas torus is huge—one million kilometers thick—but most of it is too thin to be habitable. The central part of the Gas Torus, where the air is thicker, is known as the Smoke Ring. The Smoke Ring supports a wide variety of life. No "ground" exists in the Smoke Ring; it consists entirely of sky. Furthermore, the Smoke Ring is in orbit and therefore in free fall: there is no "up" or "down"."
The settlers of Citizen Tree are unexpectedly introduced to tree logging when a logger vessel approaches their tree. The logging vessel is on fire and the settlers rush to help the loggers battle the flames. Four people are rescued but one doesn't make it, too badly hurt in the explosion that caused the fire.
The newcomers are welcomed and it is assumed they will become part of Citizen Tree's small community. But the settlers didn't know about the logging and the propulsion system used to pilot the logging vessel. Most of which is centered around equipment brought to the Smoke Ring five hundred years ago by their ancestors from Earth. As the newcomers tell of their life of harvesting the integral trees and of bringing the wood to be sold at the market at the Admiralty, the settlers are intrigued. The Admiralty uses technology that came from Earth and it has quite a large population of several thousand humans compared to most of the communities surviving in the Smoke Ring.
But Citizen Tree has technology too. It has a Silver Suit and a CARM vehicle which stands for Cargo And Repair Module. The Silver Suit is an armored space suit.
Due to their five hundred plus years inhabiting the Smoke Ring, which is a weightless environment, most human have become much taller and much thinner. So the average person cannot fit into one of the Silver Suits. But occasionally a throwback is born which they call dwarfs. The dwarf humans are of a size to comfortably wear the space suit.
Sailing above the Smoke Ring is the Discipline, the ship that brought humans to the Smoke Ring. It is being piloted by a computer that goes by the name of Kendy and Kendy is in contact with a few of the people of Citizen's Tree. Kendy wants to help humans survive more successfully and so it encourages a small group of settlers to take the CARM and travel to the Admiralty. They will be accompanied by two of the tree loggers who are familiar with the life and customs of those who run the Admiralty.
They will have adventures and learn many things and meet many people and as Kendy monitors from above, it comes to realize that they don't really need its help or guidance and are quite capable of figuring things out on their own.
This was a more enjoyable read than the first book, The Integral Trees, simply because it concentrates less on the science and more on the story. It's really an adventure story and a bit lighter in tone than the first book was. It's a strange weird place for humans to be living, the Smoke Ring. And it does strange weird things to human bodies as they gradually adapt to life in a weightless environment. Certainly well worth reading.
Here is a review by Publishers Weekly.