Note: The Asimov/Silverberg novel "Nightfall" is organized in 3 parts, "One Twilight", "Two Nightfall" and "Three Daybreak". The text of Asimov's novelette "Nightfall", from Astounding September 1941, is included within the "Two Nightfall" part of the book, from the beginning of Section 20 to the end of Section 27. The book is made up of 44 sections; the 8 Sections from 20 to 27 include Asimov's original text interspersed with Silverberg additions. Additionally, some of the names and related information were changed in the original text.