One of science fiction's legendary science fiction writers, Isaac Asimov, is best known for his series of interlocked stories depicting an extensive future history of humanity. This was not his original plan: the multiple series that he wrote to depict this—the Robot series, the Empire series and the Foundation series—were only linked together later in his career and after several of the novels were already written. Science-fiction fans, despite the subsequent set of occasional internal inconsistencies he introduced in doing so, rejoiced. The stories are popular and fertile enough that stories are still being written in it today, as evidenced by the recent publication of Isaac Asimov’s I Robot: To Obey by Mickey Zucker Reichert. This is the third part of a look at Asimov's extensive future history. In Part 1, we looked at Asimov's Robot and Empire stories. In Part 2, we looked at Asimov's Foundation novels. But did you know that there were other authors that contributed to this universe?

Roger MacBride Allen's Caliban Series

One of the hallmarks of Isaac Asimov's Robot stories was his Three Laws of Robotics, a set of rules that govern a robot's safety, utility and self-preservation. In the 1990s, Roger MacBride Allen upended this notion when he wrote a trilogy of books that explored robots that do not conform to those laws. Instead of having positronic brains in which the Three Laws are ingrained, Allen's robots have gravitonic brains, which can be programmed differently. The titular robot of Caliban (1993) is an experimental gravitonic robot who was created with no laws whatsoever, an experiment that was to be conducted in a controlled environment to see how his behavior evolved. Caliban escapes the laboratory and is hunted by police when it is believed he has killed his creator. In Inferno (1994), named after the planet on which these stories occur, Allen further explores the issues around the New Law robots with another murder mystery. Utopia (1996) concludes Allen's examination of the Three Laws and New Laws against a backdrop of planetary destruction by introducing a comet set to strike the ecologically bereft planet Inferno.

The Second Foundation Trilogy by The Killer B's

In the late 1990s, three distinguished hard science-fiction authors (Gregory Benford, Greg Bear and David Brin—collectively known as "The Killer B's") paid homage to Isaac Asimov's much loved Foundation trilogy with a brand new trilogy. Written some 40 years after the original, they tended to include science and science fictional tropes that were congruent with that current era. So, you will see things that Asimov himself never included in his original trilogy, like artificially intelligent sentient simulations and cyborgs.

Foundation's Fear by Gregory Benford (1997) takes place between the first and second parts of Asimov's prequel novel Forward the Foundation. In it, Hari Seldon—the mathematician who developed psychohistory, a way predict the future of large numbers of people—is appointed against his will by the Emperor as the First Minister of the Galactic Empire, a role that Hari doesn't necessarily want as it interferes with his psychohistory project.

Foundation and Chaos by Greg Bear (1998) sees Hari Seldon on trial for treason, the beginnings of the Galactic Empire's migration to Star's End, and a humaniform robot that is no longer compelled by the Three Laws. The novel takes place roughly at the time of the first part of Asimov's first Foundation novel and actually focuses less on Seldon than it does on the robot R. Daneel Olivaw, who struggles against a faction of robots opposed to his plans for humanity.

Foundation's Triumph by David Brin (1999), also taking place at the time of the original Foundation novel, sees Hari near the end of his life while his wife becomes involved with a robot rebellion. The story simultaneously wraps up the loose ends of the new trilogy and connects it to the original novels.

More Robot and Foundation Books 

There are even more books related to Asimov's sprawling Robot/Foundation universe. For starters, there is Isaac Asimov's Robot City, a series of standalone novels written by various authors between 1987 and 1988 that are only loosely connected to Isaac Asimov's Robot series. They take place between The Robots of Dawn and Robots and Empire. Another follow-on series, Isaac Asimov's Robots and Aliens (1989-1990), further explored the relationship between its characters and the robot-run cities in which they lived.

Foundation's Friends (1989), edited by Martin H. Greenberg, is an anthology of 18 Robot/Foundation stories by the likes of Ben Bova, Pamela Sargent, Robert Silverberg, Harry Turtledove, Connie Willis, Mike Resnick, Sheila Finch, Frederik Pohl, Orson Scott Card and more. If you like short fiction and enjoyed Asimov's Robot/Foundation stories, this is a fun read. 

Psychohistorical Crisis by Donald Kingsbury (2002) is a re-imagining of Asimov's famous Foundation trilogy, set after the establishment of the Second Empire. Although obviously patterned after the Foundation, it distances itself from the original copyrighted material by using transparent (but obvious) name changes.

Fans of the series will also want to check out I, Robot: The Illustrated Screenplay by Harlan Ellison. Ellison's screenplay is truer to the source material—certainly more so than the 2004 film adaptation starring Will Smith.

Mickey Zucker Reichert's I, Robot Series

As proof that Asimov's universe is still fertile ground for numerous stories, I submit a new, in-progress trilogy, the I, Robot series written by Mickey Zucker Reichert. This trilogy explores the life of the woman who started it all: Dr. Susan Calvin, the scientist who invented the positronic brain that's ingrained with the venerable Three Laws of Robotics.

The first book, I, Robot: To Protect (2011), shows Susan Calvin at the beginning of her residency at a teaching hospital, where nanorobots are used to map the human mind. When Susan begins to question a suspicious sequence of events, she becomes involved in a conspiracy that could have dire consequences. The second book, the newly released I, Robot: To Obey (2013), further depicts Susan's dealings with those who would choose to eradicate the latest technology and those who want to control it for their own nefarious ends.

John DeNardo is the editor of SF Signal, a Hugo Award-winning group science-fiction and fantasy blog featuring news, reviews and interviews. You can follow him on Twitter as @sfsignal.