Spock Must Die! is a Star Trek

Star Trek: The Original Series

Star Trek is an American science fiction television series created by Gene Roddenberry, produced by Desilu Productions . Star Trek was telecast on NBC from September 8, 1966, through June 3, 1969...

 novel by James Blish

James Blish

James Benjamin Blish was an American author of fantasy and science fiction. Blish also wrote literary criticism of science fiction using the pen-name William Atheling, Jr.-Biography:...

 released in 1970. It was published by Bantam Books

Bantam Books

Bantam Books is an American publishing house owned entirely by Random House, the German media corporation subsidiary of Bertelsmann; it is an imprint of the Random House Publishing Group. It was formed in 1945 by Walter B. Pitkin, Jr., Sidney B. Kramer, and Ian and Betty Ballantine...

. It is notable as the second of hundreds of original novels to be based upon the Star Trek

Star Trek

Star Trek is an American science fiction entertainment franchise created by Gene Roddenberry. The core of Star Trek is its six television series: The Original Series, The Animated Series, The Next Generation, Deep Space Nine, Voyager, and Enterprise...

franchise.

Blish also was writing an ongoing series of novelizations

Star Trek (Blish)

James Blish wrote a series of short stories adaptations of Star Trek episodes from 1967 to 1975, called simply Star Trek. The adaptations were generally written based on scripts , and initially without reference to the finished episodes, as they had not yet aired in the United Kingdom, Blish's base...

 of Star Trek episodes.

Plot

The Klingon

Klingon

Klingons are a fictional warrior race in the Star Trek universe.Klingons are recurring villains in the 1960s television show Star Trek: The Original Series, and have appeared in all five spin-off series and eight feature films...

 Empire manages to imprison the Organian

Organian

The Organians are a fictional race in the universe of Star Trek, appearing in the episode "Errand of Mercy." They are one of the most evolved, advanced alien races ever encountered by the crew of the original Enterprise. It is not known whether they are "moral" beings or, because they have no...

s and begin another war with the Federation. Captain Kirk and the crew of the U.S.S. Enterprise

USS Enterprise (NCC-1701)

The USS Enterprise, NCC-1701, is a fictional starship in the Star Trek media franchise. The original Star Trek series depicts her crew's mission "to explore strange new worlds; to seek out new life and new civilizations; to boldly go where no man has gone before" under the command of Captain James...

 find themselves far behind enemy lines.

Scotty

Montgomery Scott

Montgomery "Scotty" Scott is a Scottish engineer in the Star Trek media franchise. First portrayed by James Doohan in the original Star Trek series, Scotty also appears in the animated Star Trek series, seven Star Trek movies, the Star Trek: The Next Generation episode "Relics", and in numerous...

 has figured out a way to use tachyons to send a duplicate of Mr. Spock to Organia faster, without having to travel through Klingon space, but something has gone terribly wrong. As a result, there are now two Mr. Spocks. Eventually, one of them turns out to be an evil saboteur

Saboteur

A saboteur is someone who commits sabotage.It may also refer to:*Morituri , a 1965 film also known as The Saboteur*Saboteur , a card game by Frederic Moyersoen, published in 2004...

 and has to be destroyed... but which one?

The novel is notable for an elementary public exposure of tachyon

Tachyon

A tachyon is a hypothetical subatomic particle that always moves faster than light. In the language of special relativity, a tachyon would be a particle with space-like four-momentum and imaginary proper time. A tachyon would be constrained to the space-like portion of the energy-momentum graph...

 theory.

For a similar duplication of Captain Kirk, see "The Enemy Within" (TOS episode)

The Enemy Within (TOS episode)

"The Enemy Within" is an episode of Star Trek: The Original Series. It was first broadcast on October 6, 1966. It is the fifth episode of the first season, and was written by Richard Matheson and directed by Leo Penn....

.