Star Trek : Assignment - Eternity (Star Trek: The Original Series #78) -

Greg Cox

Pocket Books / Star Trek

1998

278 páginas

9h 16m

ISBN-10: 0671855360

On an urgent mission to bring relief to a disaster-ravaged planet, Captain Kirk is forced to trust time-traveling alien Gary Seven, who harbors a personal agenda that may spell destruction for Kirk's own era.

The genesis of Assignment: Eternity came from editor John Ordover, who suggested telling a story featuring the abandoned characters of Gary Seven and Roberta Lincoln. Greg Cox took up the assignment and made his mark.
====
https://them0vieblog.com/2015/01/05/star-trek-assignment-eternity-by-greg-cox-review/
As for the Eugenics Wars books, I had actually set that up at the end of the previous Seven/Roberta novel (mentioned above), where Spock mentions to Kirk that his historical research had revealed that Gary and Roberta had been instrumental in the overthrow of Khan Noonien Singh. Honest to God, at the time I wrote that I didn’t have any sequels in mind; I just thought it made a nice punchline to Assignment: Eternity. Then John asked me if wanted to write that story…