The novel follows two different storylines, which gradually begin to converge. The first story is of Grünberk Braun, a member of the European Union Intelligence Board who discovers a Mind Virus that seems to have come from a lab in San Diego, California, and of his colleague, Albert Vaz of India's External Intelligence Agency, an expert Braun quickly turns to. Unfortunately, Vaz is the man secretly behind the virus, which he believes is the only way to end terrorism forever. The second story is of Robert Gu, a world-famous poet, who has recently been cured of his Alzheimer's and given rejuvenation treatments, and is now living with his son in San Diego and learning to cope with the changes in the world in the years since he started becoming senile.
The team formed by Braun and Vaz decide that a direct approach to the American government would be too risky—the Americans might be behind the virus. So, posing as South American drug lords, they approach a secretive hacker known as The Rabbit to help them find a way into the San Diego labs. Meanwhile, Robert Gu has discovered that the library at the University of San Diego is about to be digitized using a destructive process that shreds the physical books. Dismayed, he joins a group seeking to stop this action, known as the Librareome Project. As it turns out, The Rabbit has his own plans for the anti-Librareome group.
The book spends a lot of time exploring the implications of "wearables"—powerful, light-weight networked computers that use contact lenses or glasses for display, and subtle gestures for input; a logical extension of today's smartphone technology. Wearables are as common in the world of Rainbows End as cell-phones are today, especially among the young.
Rainbows End won the Hugo Award in 2007.
Tropes in this work:
- Augmented Reality: "Wearables" provide this through smart contact lenses (among other things). You can build custom views of things, but most people prefer to participate in one of the many overlapping shared virtual worlds, usually based on popular works of fiction, like Discworld. (Vinge mentions that royalties from the Discworld virtual reality have allowed Terry Pratchett to buy up a substantial chunk of Scotland.) Basically, you can participate in a Massively Multiplayer Online Role-Playing Game while walking down the street.
- Black Box: Pretty much all engineering is done by putting together modular black boxes whose contents are unknown, except to the companies that manufacture them. This is done to protect copyrights and trade secrets. Plus, it's supposed to make things simpler. At one point, Robert Gu gets frustrated, and tries to open a black box under the hood of a car, using a kind of matter beam (using ball bearings!). The result is an explosion.
- Books That Bite: The library at the University in San Diego has these, although they're purely virtual and only visible to people who are "wearing". Nevertheless, they're as real as any of the other e-books the library has. They were created as an in-universe Shout-Out to Discworld.
- Chekhov's Lecture: Ms. Chumlig's lesson on "Search and Analysis."
- The Chessmaster: This is Mr. Rabbit's talent.
- Data Pad: Considered obsolete but still available. Robert Gu starts with one thin enough to be folded up like a piece of paper after his Alzheimer's is cured.
- Did Not Die That Way: Robert Gu discovers—though we knew it all along—that his wife hated him so much that she faked her own death (with the help of Friends of Privacy) when she learned that a cure for his advanced Alzheimer's had been found.
- Digital Avatar: The widespread use of "wearable" computers makes this extremely common. The hacker known as Rabbit actually appears as a giant rabbit, for example.
- Digitized Hacker: It's strongly suggested that Mr. Rabbit is this, especially when, with moments to go before before his connection to the group beneath the lab is cut off, he manages to leave them with a detailed PDF document titled, "While We Are Out of Touch or How To Survive and Prosper During the Next Thirty Minutes", with explanations of the whole situation, who's responsible, what they can do about it, and much more.
- Fan Dumb: In-Universe, Rabbit manipulates two opposing fandoms into a full-scale riot outside the Geisel Library.
- Fish out of Temporal Water: Robert Gu has been suffering from Alzheimer's since more-or-less the present day, and wasn't much interested in technology then. Twenty Minutes In The Future, when he's cured and given rejuve treatments, he's so far behind the curve on everyday technology that he needs to start attending classes at the local high-school just to begin to have a hope of getting by in normal society.
- Futuristic Superhighway: Cars in the novel are quite futuristic, but there is not much need for superhighways themselves precisely because of how much cars have changed. Most cars are not privately owned but automatically drive themselves to wherever they are needed, acting as a sort of automated, fast, incredibly efficient taxi service. This keeps transit efficient, and roads normal-sized. The biggest indicator of futuristic roads is omnipresent transit loops, roadways where automatic cars briefly stop to drop off and pick up passengers.
- Instant Expert: Technology — called Just In Time Training (JITT) — exists to allow this, but its side-effects are so severe that it's completely banned outside the intelligence community.
- Insufferable Genius:
- Robert Gu is considered one of the greatest living poets, and he loves using his gift of language to humiliate others and put them in their place. When she finds out his Alzheimer's is being cured, his ex-wife fakes her own death, rather than have to face him again.
- Rabbit likes to lord his technical prowess over others.
- Longevity Treatment: The Venn-Kurasawa treatments. They only work for one in a thousand, but for those they do work for, they can restore the appearance of youth, and add many years of actual lifespan. Robert Gu is one of the lucky few who respond to the treatments.
- Massively Multiplayer Online Role-Playing Game: The development of "wearables" has made these even more common and popular than they are today. People can and do play them on the streets, while traveling to work or school.
- Meaningful Name: Alice and Bob Gu, named for the traditional placeholders when discussing cryptography.
- Mind Virus: The YGBM ("You Gotta Believe Me") virus.
- Mole in Charge: When Grünberk Braun discovers the existence of the Mind Control virus, he asks for help from Albert Vaz, the man who has secretly created it as part of his plan to save the world from itself.
- Moving Buildings: The library at the University of California in San Diego is designed to move under computer control in case of earthquake. At one point, hackers take over the building's computers during a public demonstration, to make the building dance along to the music. It doesn't work quite as planned.
- Multiethnic Name: Robert Gu (Sr. and Jr.) reflects the melting pot nature of modern (and near-future) America. The Indian national named Albert Vaz, on the other hand, suggests that the rest of the world is becoming more of a melting pot as well.
- Not-So-Harmless Villain: Vaz and his confederates believe Rabbit is a buffoon and intend to use him as their Unwitting Pawn. Turns out, the reality is closer to the reverse.
- Ragtag Bunch of Misfits: The Library Cabal, who are ostensibly trying to stop the destructive digitization of the library's contents.
- Self-Deprecation: One character muses on belief circles that made Augmented Reality fan art so unpopular it served as a Franchise Killer for the works it was based on. One of the franchises he mentions is Vernor Vinge's own Zones of Thought.
- Sequel Hook: Quite a few. Rabbit may or may not be gone, may or may not be an A.I., and may or may not be subtly making good on his deals with the Elder Cabal. Albert Vaz's fate is left ambiguous. The Great Powers are going nuts over the realization that the Secure Hardware Environment has been subverted, leading Alice Gu to return to Just In Time Training. And Robert Gu is still working to rehabilitate his relations with his family.
- Shout-Out: Rabbit likes to address people as "Doc." "Egan soccer" is the 'quantum soccer' invented for Greg Egan's short story "Border Guards".
- Smug Snake: Rabbit is brilliant, but nobody is as brilliant as he thinks he is.
- Synthetic Plague: The Sunrise Plague was an artificial pseudomimivirus released by a cult, and the "second worst Euro-terror of the decade". A large part of the book revolves around the search for a new virus designed not to kill, but for Mind Control.
- The Trickster: Rabbit deliberately invokes this archetype, teasing both friends and foes with his technological prowess and bizarre sense of humor. He likes to leave virtual carrot ends in other people's virtual worlds.
- 20 Minutes into the Future: Many people in the book are supposed to have already been alive at the time the book was written, such as William Blount, who was Dean of Arts and Letters at Stanford University until 2012. (In the book.)
- Tyop on the Cover: in-universe. Rainbows End (with no apostrophe) is the name of a retirement home. One of the characters wonders if this was deliberate.
- Well-Intentioned Extremist: Albert Vaz has created a Mind Control virus because he sincerely believes it's the only way to keep the world safe, when even terrorists and cults can afford nukes and deadly viruses.
- What Do You Mean, It's for Kids?: In-Universe, saying that "Scooch-a-mouti" is a children's franchise is the Berserk Button of its adult fandom.