Star Trek: The Original Series: Shadow of the Machine, an eNovella by Scott Harrison, will be released in March by Simon & Schuster/Pocket Books. Here's the synopsis, straight from the publisher:
An all-new original e-novella set in The Original Series universe—taking place immediately after the events of the 1979 film Star Trek: The Motion Picture!
After its recent encounter with V’ger, the U.S.S. Enterprise has returned to dry dock to finish its refit before commencing its continuing mission. The crew has been granted a two-week period of shore leave before preparations for their next voyage begins. Shaken by their encounter with V’ger, Kirk, Spock and Sulu travel to their respective homes and must reflect upon their lives—now forever changed.
Star Trek: The Original Series: Shadow of the Machineamazon.com