The Entropy Effect
The Entropy Effect is a Pocket TOS novel, written by Vonda N. McIntyre. The first original novel published by Pocket Books, it was first released in .

Summary
From the book jacket 
THE UNIVERSE HAS LESS THAN A CENTURY LEFT… UNLESS SPOCK CAN CHANGE HISTORY!The  is summoned to transport a dangerous criminal from starbase prison to a rehabilitation center: brilliant physicist, Dr. Georges Mordreaux, accused of promising to send people back in time – then killing them instead.

But when Mordreaux escapes, bursts onto the bridge and kills Captain Kirk, Spock must journey back in time to avert disaster – before it occurs!Now there's more at stake than just Kirk's life. Mordreaux's experiments have thrown the entire universe into a deadly time warp. Spock is fighting time … and the universe is closing in on itself with the relentless squeeze of …

THE ENTROPY EFFECT

 

A priority message summons the  to the mining colony Aleph Prime, interrupting Spock's study of a new singularity before he can confirm his findings, which seem to indicate that the Universe has less than a century of life left to it.

On Aleph Prime, prosecuting attorney Ian Braithewaite – who finds Spock oddly familiar – claims that no such message was sent; however, since the ship is now here, he asks Kirk to transport a dangerous prisoner to Rehab Colony Seven. Spock is surprised to learn that the prisoner is the noted scientist Dr Georges Mordreaux, who has been found guilty of murder and experimenting on unwilling subjects. Convinced that there's more to the story, Spock orders new security chief Mandala Flynn to have Mordreaux confined to a VIP cabin rather than the detention cells, and to discontinue the regime of drugs that have reduced him to a state of near catatonia.

Kirk is reunited with an old flame, Captain Hunter, and Sulu, who has been considering a transfer for some time, applies for and receives a transfer to Hunter's ship, the Aerfen. Before Sulu leaves, he and Flynn confess their love for each other, but agree that this is the best move for Sulu's career.

The Enterprise sets off for Rehab 7, but Scotty catches a glimpse of Spock in the transporter room when he should be on the bridge, and Spock refuses to explain the discrepancy. Mordreaux escapes from custody and forces his way onto the bridge, where he injures Braithewaite and shoots both Kirk and Flynn with spiderweb slugs, bullets that choke the Human nervous system with organo-metallic fibers. However, the security detail insists that Mordreaux never left his cabin, and a search turns up no sign of the gun. Kirk is soon brain-dead, and Spock convinces the reluctant Doctor Leonard McCoy to terminate life support; however, the semi-conscious Braithewaite misinterprets what he's seeing. Believing that he saw Spock on Aleph Prime before the Enterprise arrived, he becomes convinced that Spock and McCoy are in league with Mordreaux and have deliberately killed Kirk.

Spock questions Mordreaux, who reveals that he's invented a method of time travel that he used to send his friends into the past, where they felt they could find a better life. His discovery has been suppressed by higher-ups in the Federation who fear its potential as a weapon, and he was framed for murder and his research destroyed. It seems that a future version of Mordreaux is responsible for murdering Kirk, and the present-day version agrees to help Spock construct a time-changer to put matters right on condition that Spock not betray Mordreaux's friends.

Spock travels back in time, but fails to save Kirk – and he is spotted in the transporter room by Scott, rousing the engineer's suspicions when the past version of Spock claims never to have been there. Spock returns to the present, where Braithewaite and Scotty now believe that he and McCoy are conspiring to free Mordreaux. Hunter and Sulu return to the Enterprise to help investigate, just as Spock uses the time-changer to go further back – this time to Aleph Prime. McCoy tries to cover for him, but is eventually forced to admit the truth, and despite the lack of evidence, Hunter agrees to give Spock twelve hours in the past when Sulu speaks up on his behalf.

Spock bumps into the younger Braithewaite in Aleph Prime, explaining why the prosecutor believed he'd been there before. He tries to stop Mordreaux from sending the call that summoned the Enterprise, but discovers too late that he's stunned yet another version of Mordreaux, who had traveled back in time to stop his younger self from committing murder. Mordreaux explains that his experiments have caused the entropy effect that Spock noticed, shortening the Universe's life span to less than a century; the knowledge drove him mad, and he traveled back in time to take his revenge on those who'd allowed him to live – including Kirk, who helped Spock defend Mordreaux in the timeline in which he was sent to rehabilitation.

The older Mordreaux releases Spock from his promise, and Spock goes back one last time to convince the younger Mordreaux not to send his friends back through time in the first place. Mordreaux and his friends are skeptical until the older Mordreaux materializes before their eyes and crumbles to dust, his body finally succumbing to the strain of this dangerous means of time travel. Realizing that his older self found death preferable to living with what he'd done, the young Mordreaux agrees to abandon his research of his own accord. Spock returns to the present, where he destroys the time-changer and finds that the Universe is now safe, since none of these events ever happened. 

Memorable quotes
"Hikaru, let me give you some advice. Nobody will believe in you for you."
 - Mandala Flynn

"I shall endeavor not to return before I leave."
 - Spock, in all seriousness, on his attempt at time travel

 Background information 
 This was the first original Star Trek novel published by Pocket Books, and the first of hundreds to be published over the next four decades. It was published only two months after the final Bantam Books release, Death's Angel. Although Pocket had published the novelization of  in late 1979, it held off on publishing any original novels until Bantam released the final three novels of its contract.
 This represents the first use of Sulu's first name, Hikaru. It was not officially established, however, until . The original cover art of the novel also depicts a long-haired version of Sulu with a long Asian-style mustache, as he is depicted in the novel (because of a bet with Commander Flynn).
 Other novels by the same author are particularly complimentary to Sulu, whom she described in prose in the novelization of  as "the good-looking Asian man." Flynn (by that time promoted to captain, and given a command) is also mentioned in the novelizations  and  by the same author. 
 Some of Sulu's back story is revealed in this novel. Sulu's mother is a consulting agronomist. His father is a poet. He was born on Earth (consistent with ), but spent his childhood and adolescence on a succession of colony planets. He receives his promotion to lieutenant commander here.
 Sulu is shown here learning judo from Mandala Flynn. He was later seen on screen using a judo move on a security officer in . Sulu also uses a judo move in , in which Kirk even asks Sulu to teach him that particular technique. The Pocket Books timeline places this novel after that episode, however this novel's stardate would place it before the events of .
 The minor character Ilya Nikolaievich is possibly a reference to the character  of , a show which aired contemporaneously with . Both shows were followed by post-cancellation syndication of the existing episodes, as well as feature films and novels based on each series; and among each show's viewer base were dedicated fans who together formed the burgeoning media fandom movement. The novel's author is a self-described "huge fan of the show" and particularly of Illya Kuryakin  and not only Ilya's name but also his physical description – "shorter than Sulu, but similar in build: compact and well-proportioned […] His heavy straight blond hair fell across his forehead" (p. 109) – hair-trigger reflexes, and Spock-like self-control are all notably reminiscent of David McCallum's Russian character. McIntyre's spelling of her character Ilya Nikolaievich's name is also a "correct" spelling of Kuryakin's first name and patronym in standard Cyrillic-to-English Latin transliteration and the Russian language rules for patronymic formation,  lending further support to the reading of the character in the novel as intentionally resembling the Man From U.N.C.L.E. character. 
 This novel, written prior to the release of , strongly implies that Kirk has no children.
 The crew of the Enterprise numbers four hundred thirty-five people at this point.
 According to this novel, Vulcans don't lock their doors.
 The audiobook abridgment removes the Sulu subplot – as a result, the cover of  is used on the packaging.
 The original cover art shows the crew in -era uniforms and the TMP refit of the USS Enterprise, but the novel is set during the TOS time frame. Later novels suggest that the TMP-era uniforms were being introduced toward the end of the original five-year mission, but the movie explicitly indicates that the refit occurred after the mission's completion. This disconnect between cover art and setting continues across a number of the early Pocket Books releases.
 A limited edition hardcover was printed by Gregg Press in 1984.
 The novel was one of four to be re-released with an updated cover in late  to honor Star Treks 40th anniversary.

 Cover gallery 

 Characters 
 Enterprise crew 

 James T. Kirk  Captain
 Spock  Science Officer
 Leonard McCoy  CMO
 Montgomery Scott  Chief Engineer
 Uhura  Communications officer
 Hikaru Sulu  Helm
 Pavel Chekov Navigator
 Janice Rand  Yeoman
 Christine Chapel  Nurse
 Mandala Flynn  Chief of Security
 Jenniver Aristeides  Security officer
 Maximo Alisaunder Arrunja  Security officer
 Bernardi al Auriga  Security officer
 Neon  Security officer
 Snnanagfashtalli  Security officer
 Beatrice Smith  Enterprise crew

 Aerfen crew 
 Hunter  Captain of Aerfen Ilya Nikolaievich  Aerfen crew

 Aleph Prime characters 
 Ian Braithwaite  Prosecuting Attorney
 Georges Mordreaux  Scientist
 Mree
 Perim
 Lee Defense Attorney

 Mentioned 
 Peter Kirk  Nephew of James T. Kirk
 Friendly A senior-class student during Kirk's time at Starfleet Academy

 References 
; Klingons; mind meld; Starfleet Academy; time travel; Vulcan
   Starfleet fighter vessel commanded by Captain Hunter, part of a border patrol squadron.
 Aleph Prime  Federation mining colony.
 Arcturus  A mostly neutral territory almost exactly equidistant from Federation, Romulan, and Klingon space.
 Gamma Draconis VII
 Ganjitsu  Federation border colony with a history of harassment by Klingons. Once home to Hikaru Sulu.
 Makropyrios  Federation university.
 Mitra'' : Trading vessel. Mandala Flynn's parents were part of its crew. The vessel was destroyed and no trace of them was ever found. 
 Rehabilitation Colony Seven

External links 
 
 

de:Der Entropie-Effekt
Novels
Audiobooks