Riverworld is a planet covered by one long, long river, winding back and forth and up and down from pole to pole. Adjacent banks are separated by unscalable cliffs, necessitating travel by foot along the banks of The River, or by some kind of river craft. But there are rare exceptions.
If you were a human being who was more than five years old when you died, and if you lived and died any time beyond 99,000 B.C. up to and including 1983 A.D., you are resurrected along the banks of The River. If you lived and died beyond 1983, you will also be resurrected there, but you are not in this particular Riverworld saga. Famous persons who are in this saga are Mark Twain, Jack London, Hermann Goring, and Mozart. Less famous persons are numerous, including Sir Richard Francis Burton, Alice Liddell, Cyrano de Bergerac, and Tom Mix.
The story involves characters trying to discover who built Riverworld and why it was built. Mysteries arise, secrets are revealed, hardships and treacheries are endured. Eventually, after some twists and turns, everything comes to light.
Five novels are included in the four volumes of Tor's latest trade-paperback editions. The first volume, RIVERWORLD, contains the first two novels: TO YOUR SCATTERED BODIES GO and THE FABULOUS RIVERBOAT. These two are short, but they are agreeably paced and stick to the storyline. Increasingly as you progress through DARK DESIGN, THE MAGIC LABYRINTH, and GODS OF RIVERWORLD, more and more passages are slow. Depending on the reader, they are not necessarily bad, but neither are they necessary for the progression of the story. For example, we get mini biographies of some of the historical characters. Also, particularly in the last two books, characters think and talk about philosophical issues, like the human soul.
Despite the questionable material, Philip José Farmer's prose is very accessible. But I think it is unfair to include content like the questionable material, which many if not most readers neither expect nor want when they look for science fiction. Therefore, to caution you about this material, I lower my rating by one star.
If you can overlook the unorthodox content, go ahead and give the series five stars. The story is a classic, smartly contrived, putting you in touch with concepts that you will never forget.