The Lost Years tells the stories of the Star Trek: The Original Series characters in the years between the end of the five-year mission and the events of Star Trek: The Motion Picture. The concept was derived by Robert Greenberger, and the series was originally intended as a trilogy, starting with a "Giant" novel by J.M. Dillard.
The four novels included in the box set are: - TOS: The Lost Years - TOS #54: A Flag Full of Stars - TOS #70: Traitor Winds - TOS #73: Recovery