

Vampires are non-sentient hominids who exude a sexual allure to attract prey - humans. Vampires are proliferating at an alarming rate, threatening other species. Their technology is minimal and some species are non-sentient.The third book in the series, "Ringworld Throne," takes place after a cataclysmic threat to the Ring has been averted by Earth spaceman Louis Wu (and friends), at the expense of the lives of many inhabitants.The Hindmost, an alien watcher exiled from his own world, calls Wu's attention to a new threat to the Ringworld. The builders of this place vanished before human history on Earth began.Inhabiting this Ring are numerous human species with different skills, diets and requirements, who mostly live in peace due to lack of competition for food and habitat.

With the fourth volume in that series appearing this summer ("Ringworld's Children"), fans may want to refresh their memories - it's been almost ten years.The series is set in an artificial habitat built as a 600-million-mile ring around a sun-type star, with orbiting sunshades to provide day and night and thousand-mile-high rim walls to prevent the atmosphere from spilling out. In 1970 Larry Niven's "Ringworld"won the Nebula and Hugo awards for best novel.
