Contains a story by Terry Pratchett, around which Stewart and Cohen write about the Discworld.

Frontiers probes the furthest boundaries of prehistory, science, earth space and the universe. It is a collection of short, topical and intriguing essays through which Isaac Asimov, the incomparable writer of science fiction, proposes brand new answers to classic scientific conundrums.

Published by Avon Books, 1983, this First Paperback Edition has 253 pages. Isaac Asimov was considered to be one of the big three authors who brought science fiction into the American households.