Editing Ringworld (section)

==Plot summary==
On [[Earth]] in 2850 AD, a bored [[Louis Wu]] is celebrating his 200th birthday. Despite his age, Louis is in perfect physical condition due to the [[Longevity|longevity drug]] [[Known Space#Boosterspice|boosterspice]]. [[Nessus (Pierson's Puppeteer)|Nessus]], a [[Pierson's Puppeteers|Pierson's puppeteer]], offers him a mysterious job. Intrigued, Louis accepts. Nessus also recruits the [[Kzin]] [[Speaker-to-Animals]] and [[Teela Brown]], a young human woman who becomes Louis's lover, for the rest of the ship's crew.

On the puppeteer home world (which is fleeing deadly radiation that will arrive in 20,000 years), they are told that their goal is to determine if the Ringworld, a gigantic artificial ring near the puppeteers' path, poses any threat to their migration. The Ringworld is about one million miles (1.6 million km) wide and approximately the diameter of Earth's orbit, encircling a sunlike star. It rotates to provide artificial gravity 99% as strong as Earth's from [[centrifugal force]]. It has a habitable inner surface (equivalent in area to approximately three million Earths), a breathable atmosphere, and a temperature optimal for humans. Night is provided by an inner ring of shadow squares which are connected to each other by thin, ultra-strong wire. When the crew completes its mission, as payment they will be given the starship they used to travel to the puppeteer world; it is about 1000 times faster than any human or Kzinti ship.

When they reach the vicinity of the Ringworld, they are unable to contact anyone. Their ship, the ''Lying Bastard'', is disabled by an automated [[meteoroid]]-defense system. The vessel collides with a strand of shadow-square wire and crash-lands near a huge mountain, which is called "Fist-of-God" by the first natives they speak with. The fusion drive is destroyed, so they set out to find a way to get the ''Lying Bastard'' off the Ringworld and use the undamaged hyperdrive to return home.

Using their flycycles, they set out for the rim of the ring, searching for technology to help them get home. They encounter primitive human natives who live in the ruins of a once-advanced city. The natives think that Louis is one of the engineers who created the ring, whom they revere as gods. The crew is attacked when Louis accidentally commits what the natives consider a blasphemy, but extricate themselves.

During their journey, Nessus reveals several puppeteer secrets. They initiated research into rendering the Kzinti extinct, considering them dangerous and useless, but found that the numerous [[Man-Kzin]] wars&mdash;which the Kzinti always lost&mdash;had greatly reduced their aggression: a very high percentage of Kzinti males were killed in each conflict, leaving more prudent and cautious survivors to breed. The puppeteers had also used Birthright Lotteries to try to breed humans for luck: all of Teela's ancestors for six generations are lottery winners. Speaker's outrage at learning the former forces Nessus to flee from the group and then follow from a safe distance.

While flying through a giant storm, Teela becomes separated from the others. When Louis and Speaker search for her, their flycycles are caught by an automated trap designed to catch speeders. They are brought to a floating police station. There, they meet Halrloprillalar Hotrufan ("Prill"), a former crew member of a ship that had brought back goods from worlds abandoned by the Ringworld builders. Nessus, using a tasp (a remote pleasure-giving device), conditions Prill into helping and joining them. When her ship returned to the Ringworld the last time, they discovered that civilization had collapsed. Louis surmises that a mold inadvertently brought back by a ship like Prill's mutated and broke down the superconductors vital to the Ringworld civilization, causing its fall.

Teela rejoins them, accompanied by her new lover, a traveling warrior named Seeker who protected her. Based on an insight gained from studying a Ringworld map, Louis comes up with a plan to get home. Teela chooses to remain on the Ringworld with Seeker. Louis, formerly skeptical about breeding for luck, now wonders if the entire mission was caused by Teela's luck, to unite her with her true love and help her mature.

The party collects one end of the shadow-square wire that snapped after the collision with their ship and fell near their path, and drag it behind them. Louis threads it through the ''Lying Bastard'' to tether it to the floating police station. "Fist-of-God", the enormous mountain near their crash site, was not on the Ringworld map, leading Louis to guess that it is the result of a meteoroid striking the underside of the ring, pushing the ring's floor up and finally breaking through. The top of the mountain, above the atmosphere, is therefore just a hole. Louis uses the police station to drag the ''Lying Bastard'' up and into the hole. Once the ship falls through and clears the ring, they can use its hyperdrive to get home. The book concludes with Louis and Speaker discussing returning to the Ringworld.