Third Nephi, The book of Nephi, the son of Nephi, is the most important book in the Book of Mormon, and perhaps the most distant from the large plates. Other book name changes can be traced to the new person established as the king or chief judge (Mosiah through Helaman). Nephi, son of Nephi, son of Helaman, does not become a ruler in this book. Thus, it is a named book that doesn’t fit the standard naming conventions found in the Book of Mormon. Although some of the content will show the markers of having been taken from the large plates, most of the record that Mormon uses is a “shorter but true account … given by Nephi” (3 Nephi 5:9).
The header for the book is also unusual in that it changes the purpose for which book headers have been used in the Book of Mormon up to this point. The traditional use of a header is to discuss the content of the book. This header reveals nothing about the content. It is a genealogy. The book will provide testimony of the risen Christ, but it begins by establishing the connection of this Nephi to the first Nephi.