Devil World
Drawn to the quarantined planet of Heartland, the crew of the U.S.S. Enterprise seeks infamous traitor Jacob Kell, who once sold out the Federations to the Klingons, and finds a world where immortality and evil rule.
Gordon Eklund
Gordon Eklund (born 1945) is a Nebula Award-winning, American science fiction author whose works include the "Lord Tedric" series and two of the earliest original novels based on the 1960s Star Trek TV series. He has written under the pen name Wendell Stewart, and in one instance under the name of the late E. E. Smith (1890–1965).
Star Trek: The Original Series
Star Trek: The Original Series consists of 36 total books. The current recommended reading order for the series is provided below.
Main series Star Trek
Related series Star Trek: The Original Series (numbered novels)
Related series Star Trek: Starfleet Academy
Related series Star Trek: The Original Series: The Eugenics Wars
Related series Star Trek: The Janus Gate
Related series Star Trek: The Original Series: Errand of Vengeance
Related series Star Trek: The Original Series: Errand of Fury
Related series Star Trek: The Original Series: Crucible
Related series Star Trek: Seekers