Part of the Star Trek Novel Verse.
Released in 2016 to celebrate the 50th Anniversary of Star Trek, Star Trek: Legacies is a trilogy set prior to and during The Original Series and consists of three books:
- Captain to Captain, by Greg Cox
- Best Defense by David Mack
- Purgatory's Key by Dayton Ward and Kevin Dilmore
In 2245, the Starship Enterprise under the command of Robert April visited the planet Usilde for a routine mission that soon turned tragic and left Captain April with an ethical and moral dilemma. For the over 20 years since the captains and first officers of the Enterprise have kept the secret found on that planet from everyone, including Starfleet.
Now, on the cusp of a major peace summit between the Federation and the Klingon Empire, the enigmatic "Number One" returns to the Enterprise on a personal mission of redemption - one that could plunge the quadrant into interstellar war.
These books contain examples of:
- Interquel: Most of the story is set during the second season of The Original Series, kicking off a few months after "Journey To Babel" and the second book takes place about one week after "Obsession".
- It's Personal: Kirk feels a strong vendetta against Bates for being a deep-cover spy on his ship.
- The Mole: Lisa Bates is a Romulan-born Human who infiltrated Starfleet on behalf of the Empire.
- My Greatest Failure: Number One believes that she is personally responsible for the loss of eight Enterprise crewmen on Usilde, and goes to great lengths to find them.