Heaven's River is the fourth book in the Bobiverse series by Dennis E. Taylor. Bob is a self-aware machine intelligence formed from the downloaded mental state of Bob Johansson, a self-describe nerd who had the foresight to have his brain downloaded onto silicon before his very untimely death (literally while walking across the street) at the beginning of the first book, We Are Legion (We Are Bob). As the story has progressed in subsequent books, Bob has figured out to make multiple copies of himself. The rub is that there are slight differences in each copy which causes the new copies to have their own personalities. Eventually there are so many copies of Bob floating around that they inhabit a cyberspace they call the Bobiverse. Each "Bob" has their own name and personality and are essentially individual "siblings" of the original.
However, just because the Bobs are virtual doesn't mean that they can't impact "meatspace." The original Bob was an expert programmer and tinkerer and the Bobs have figured out how to control many computer systems and technologies. Bobs can operate drones and avatars in order to have physical experiences and sensations via sensors that simulate what Bob can see, smell, touch, feel, and taste.
The original Bob became the artificial intelligence of a probe sent in to far outer space to explore a signal that could signify an extraterrestrial intelligence. Many of the Bobs have exploration and munificence towards other intelligences as some of their core values and in the hundreds of years since the Bobs have been exploring they have found a few intelligent aliens, typically further behind in technological development than they are. The Bobs have generally helped the aliens as much as they can.
One of the central features of the Bobiverse books are the references to "nerd" culture. There are many, many homages to Star Trek, especially due to the Bobiverse ethos of peaceful exploration of space and "doing no harm" to sentient species they discover in their journeys. It's not just Star Trek that the Bobiverse pokes fun at, however. There are often references to role-playing games, Dungeons & Dragons, Lord of the Rings, Game of Thrones and more. It's a fun way of connecting with the reader.
The Bobiverse is close to the 24th generation of Bobs at the time of the events in Heaven's River so there are literally thousands of Bobs, and some of them are exhibiting unusual behavior. One of the central tensions of the book is how do you resolve irreconcilable differences, especially with someone who you assumed you were 90-percent-plus in agreement with due to shared DNA (or software). Some of the Bobs (called Star Fleet are promoting a version of the Prime Directive where they want all Bobs to stop interacting with alien species. It turns out they are willing to go farther than other Bobs would have expected to impose their will on other Bobs and this causes much consternation in the Bobiverse as a whole.
In Heaven's River one of the Bobs (named Denver--get it?) has gone missing and some of his fellow Bobs go looking for him. When they explore the volume of space he was last known to be in they discover a huge megastructure called a topopolis, which is basically an artificial world for an intelligent alien species called Quinlans. The topopolis is gigantic, a billion miles long along the central axis, producing several billion square miles of living surface. The aliens are sorta like large otters and the topopolis has six central tributaries of a central rover flowing in it, which is why they have named the structure Heaven's River. Bill and some other Bobfriends of his use remote control-operated virtual reality called a "manny" which allows the Bobs to interact with the Quinlans and experience everything in real time during their expedition.
Basically the story in Heaven's River is split between the developing rift among the Bobs and the search for Bender disguised as Quinlans on Heaven's River. We learn a lot about the engineering of the structure and Quinlan society. One big mystery is that the Quinlans clearly do not have advanced technology, but someone built (and maintains!) the topopolis, so who is that? The other source of narrative tension is whether Bill will find Bender before they are discovered by whomever (or whatever?) is running Heaven's River discovers that an alien intelligence has infiltrated this world it created for the Quinlans.
Although quite different from the first three Bobiverse books (and significantly longer, apparently it was originally written as two books that were combined into one) it is quite effective. Another interesting feature of the Bobiverse books has been the grappling with existential questions. Are artificial intelligences really "people"? Effectively, the Bobs are immortal, as long as they have power and raw materials to build with. (In the setting of the books 3-d printers have been invented which can replicate themselves and basically any other product one has designs for, so the limiting factor is literally heavy metals and minerals found on planets.) So, facing immortality, what should the Bobs do? What would you do if you woke up and found yourself "alive" (or at least sentient and self-aware as an artificial intelligence) a hundred years in the future, with the capacity to remain in that state forever? Overall, I would say that the Bobiverse books in general, and Heaven's River specifically combine humor, adventure and philosophy in ways that are quite compelling.
Title: Heaven's River.
Author: Dennis E. Taylor.
Length: 632 pages.
Publisher: Ethan Ellenberg Literary Agency.
Date Published: September 24, 2020.
Date Read: June 6, 2021.
OVERALL GRADE: A- (3.67/4.0).