For over three decades "A Gun for Dinosaur" stood alone, an admired classic that blended exciting adventure with time travel, paleontology, and environmental science. It also seemed to cry out for sequels; there were many other ancient eras to visit and explore. Then in the early 1990s eight new adventures were published in magazines and then the book The Rivers of Time (1993). Each story features eccentric clients who are sometimes almost more trouble than Rivers can bear. The stories feature issues of animal rights, creationism versus evolution, and a character or two who seem to be trying to reenact old Hemingway safari stories. They are all good fun, and Rivers is humorous, charming, and eager to earn a living in them.