This is an original Story Outline from the Star Trek: The Original Series that I picked up as part of a set several years ago.
It is supposed to be a file copy from the personal, archived files of Gene Roddenberry.
This document is dated April 19, 1968, and is the (second) Story Outline for 'The Last Gunfight' (later became 'Spectre of the Gun') written by Lee Cronin (a.k.a. Gene L. 'Lee' Coon).
