Kirk is called to the planet Themis where Carol Marcus is in a coma with massive head wounds after a Klingon attack. Kwan-mei Suarez, who was slightly injured in the attack, meets him. They were apparently attacked with phaser fire from a clocked Klingon ship. Kirk discounts this as impossible, the Klingons don't have that capability.

In a ten year flashback, Kirk remembers his visit with Carol where he told here how David died. For a year she had been avoiding him, because the memory was too painful. She brakes down and Kirk comforts her. We find that they have spent all of there free time for the past seven years together.

Kirk is called back to Starfleet before any change in Carol's condition.

Captain Sulu, in command of the Excelsior, is returning from a three year survey of the Reydoven sector when an energy wave buffets the ship with teeth-chattering intensity. Praxis, a Klingon moon, has exploded, losing over three-quarters of its mass. The Klingons decline assistance and Sulu reports the incident to Starfleet.

At Starfleet Headquarters Kirk is reunited with the crew of the Enterprise and ordered by Admiral Smillie to rendezvous with Klingon ship bringing Counselor Gorkon to Starfleet Headquarters to sue for peace. Kirk protests to no avail and is angry at Spock for volunteering him for the assignment.

The enterprise departs for the rendezvous with Chancellor Gorkon. Lieutenant Valeris, a Vulcan from ShanaiKahr, is the new helmsman on the Enterprise. She was befriended by Saavik and sponsored at Starfleet Academy by Spock where she graduated first in her class. She overhears Kirk reflecting on the loss of his son at the hands of the Klingons and has conversations with both Kirk and Spock regarding the mission and her position on the Enterprise.

The Enterprise rendezvous with Kronos One, the Klingon vessel carrying Chancellor Gorkon to the meeting. Kirk invites the Klingons to dinner as tension builds within the crew.

The Klingons, Chancellor Gorkon, his daughter Azetbur, Brigadier Kerla, General Chang and several security guards come on board and are given a tour of the ship. After the Klingons leave the transporter room Lieutenant Valeris overhears two crewmen making races comments about the them and she reprimands the crewmen for it.
At dinner Gorkon offers a toast to the "Undiscovered Country . . . The Future." Spock asks for an explanation, "The quote clearly refers to the fear of death." Gorkon replies, ". . . it is a metaphor concerning fear of the unknown." Chang tries to bait Kirk into admitting Starfleet is primarily a military organization, that war is inevitable and the Federation is a Homo Sapiens only club. He makes the point that the Klingons will replace those on the lowest rung of the employment ladder if there is peace. The dinner ends on a hostile note.

Azetbur goes to Gorkon's room. She is concerned for his safety. He tells her he expects to be assassinated. He has made arrangements for her to succeed him on the High Council. Later Kerla comes to her quarters and asks her again to take the oath, to be his mate. {Not part of the movie}

Kirk, reflecting on the events of the evening, is called to the bridge where Spock informs him they are reading enormous amounts of neutron radiation which could only be caused by a breach in the reactor core or the arming of photon torpedoes. Moments later two photon torpedoes are fired at the Kronos One.

Gorkon is in a meeting with his aids when the torpedoes struck. The hull is breached and the gravity generator is knocked out. Two Starfleet crewmen in gravity boots and space suits enter the room. They fire blasters, not the normal Starfleet phasers, but burning phasers, illegal in the Federation. Gorkon, Kamerg and Korrd are shot along with many others. {In the movie phasers are used.}

As the Kronos One slowly turns to return fire, Kirk surrenders. Kirk and McCoy prepare to beam over to the disabled ship as Spock slaps Kirk on the shoulder leaving behind an unidentified patch. They arrive amiss the carnage and make a vain attempt to save Chancellor Gorkon. Both are arrested for the assassination of the Chancellor of the High Council.

Azetbur will not allow Kerla to perform the Klingon death chant. Her father was a man of peace, not a warrior. {This was not part of the movie.}

Spock takes command and starts an investigation of the incident.

Ra-ghoratrei, the President of the Federation, meets with the Vulcan, Romulan and Klingon ambassadors to debate the validity of Kirk and McCoy's arrest. The President states That he is not above the law. He is then visited by Three Starfleet officers, Generals Smillie and Cartwright and a Lieutenant {in the movie it is Colonel West} who explains Operation Retrieve, a plan to rescue "the hostages" Kirk and McCoy. Next he meets with several civilian advisors. Sarek is the only one present at all the meetings.

The Enterprise is ordered to return to base but Valeris {Uhura in the movie} decides they are experiencing technical difficulties.

Azetbur is names Chancellor of the High Council in her fathers place. She offers to resume the peace negotiations in a week if the President agrees not to try to rescue Kirk and McCoy. The President agrees.

Azetbur holds council with her new advisors. Most are young generals hot for war. She restrains them, focusing instead on the peace process and Kirk's upcoming trial.

Spock continues to investigate and sets a twenty-four hour limit before dealing with Starfleet.

Azetbur spurns Kerla when he proposes again. {Not part of the movie.}

The trial is witnessed throughout the Galaxy. Chang prosecutes and Colonel Worf defends. It is a show trial and goes as expected. One piece of damning evidence is Kirk's person log, where he admits hating Klingons and blames them for his sons death. This also points out that there is a traitor aboard the Enterprise. The sentence of death is commuted. They are sentenced to life on the penal asteroid archipelago of Rura Penthe, to work in the dilithium mines.

Spock comes up with the theory that the torpedoes were fired from a clocked Bird-of-Prey directly underneath the Enterprise. He orders a search of the Enterprise for the gravity boots.

Kirk and McCoy arrive on Rura Penthe and are befriended by Martia, a humanoid from Arc. She is dark skinned, golden-eyed and strikingly beautiful.

Carol Marcus regains conciseness and is told of the attack that injured her, but not of Kirk. {Not part of the movie.}

The search continues for the boots. Commander Uhura fixes her "problem" with communications and reports to Starfleet that their warp drive is inoperative. Spock reveals that he placed a viridium patch on Kirk, to track his movements.

Kirk is battling a very large alien prisoner. After taking a beating, Kirk kicks the creature in the knee. Luckily, not everybody keeps their genitals in the same place.

Sulu tells Starfleet they have no knowledge of Enterprise's location in spite of the fact that Sulu has previously offered the Enterprise any and all assistance.

McCoy is despondent and Kirk discusses escape plans with Martia.

Chekov finds Klingon Blood on the transporter pad. Spock orders the search expand to include uniforms. The gravity boots are found.

Spock interrogates Technician Dax regarding the gravity boots. Dax, a Zeosian, has large webbed feet and is quite incapable of wearing the boots.

Kirk and McCoy meet Martia at C Lift. She has changed into a large orange-haired, male simian. They go to work mining dilithium crystals. While the guards are preoccupied with lunch the simian metamorphoses into a human girl and slips out of her leg irons. She leads them through a tunnel to the surface where they make their way to the edge of the magnetic shield to wait for Spock.

The long range scanners pick up Kirk as they leave the shield. Uhura discovers that the universal translator has been sabotaged, all information on the Klingon language has been removed from their computer. As the Enterprise cross the border "cloaked". {This is one of several inconsistency in the book with the established Star Trek lore. There are several referenced to the Enterprise being cloaked. This is not consistent with any other books, the original series or TNG episodes.}

In spite of being "clocked", the Enterprise is hailed by Mortagh Outpost Three, an outdated Klingon station. Uhura bluffs her way through using an antique paper dictionary. The border guards let her pass, telling her "not to catch any bugs", a saying which, in the smuggler's code, wished her luck in avoiding border officials.

Back on the asteroid Kirk and the shapeshifter Martia fight as she changes from creature to creature. Finally she transform into a copy of Kirk and explains that Kirk and McCoy will be shot trying to escape.

Scott finds the uniforms stuffed inside a air circulation vent.

The guards show up with a sharp fanged Klingon mastiff and kill Martia-Kirk. "No witnesses," the commandant explained. Jim and Bones attempt to chicane the commandant into revealing who is behind the plot. He is about the reveal who wanted them dead when they are beamed aboard the Enterprise. "Son of a bitch!" Kirk shouts as they materialize. He explains that the conspirators name was about to be reviled. Smiling, Chekov offers to sent them back. Bones makes it absolutely clear that they will stay. Jim and Spock head for the bridge to find out where the peace conference will be held.

Aboard the Dakronh -- a Klingon Bird of Prey equipped with the latest Klingon-Romulan technology and a device that allowed her to fire while cloaked -- Chang and Grokh receive word that Kirk and McCoy have escaped.

Kirk, Spock and Scott all come together at the bodies of Yeomen Burke and Samno, the owners of the uniforms used in the assassination. Kirk takes Spock aside and explains who the killer is. A ship wide announcement is made ordering the Court Recorder to sickbay to take the statements of Yeomen Burke and Samno. Kirk and Spock surprise Valeris as she attempts to finish off her victims. Captured, Valeris reflect on the reasons behind her actions but refuses to reveal the coconspirators. Spock mind-melds with Valeris, gently, not forced as Vulcans consider that akin to rape. She reveals: Admiral Cartwright, General Chang and the Romulan Ambassador, Nanclus. {In the movie Spock becomes quite forceful.}

Sulu reveals the conference starts today at Khitomer, a planet in Klingon space near the Romulan border.

Kirk revives Spock, who is "dining on ashes," from his depression as the Enterprise rushed for Khitomer.

At Khitomer the Vulcan, Klingon, Romulan and Earth delegations prepare for the conference. As it begins, Cartwright looks around the room seeking a dark-skinned heavy-browed Klingon. He relaxes when he spots him with the small valise. Cartwright signaled and the Klingon inched toward the lectern.

Kirk, wondering what they are waiting for, is startled by Chang's voice mocking him. Then the Dakronh fires again, and again.

The Excelsior races towards Khitomer as its Chief Engineer complains to Sulu.

Chancellor Azetbur is delivering her speech as Admiral Cartwright watched the Assassin close in on her.

Kirk evades another Phaser blast and Chang taunts on. Uhura is unable to get a fix on the transmission. She suggested tracking their heat and McCoy quips, "To bad we can't smell her." Chekov chimes in with, "In space, no one can hear you sweat." And Chang keeps quoting Shakespeare. Spock detects traces of Plasma, ionized gas. The Doctor and Spock run off to rig a torpedo to home in on the gas.

Sulu arrives and takes a harmless hit.

A blast knocks out the Enterprises shields just as McCoy and Spock finish with the torpedo. Kirk fires as they all watch the torpedo looping, searching for the trail of ionized gas.

Chang smiles as Enterprise fires blindly. He sees no reason to raise Dakronk's shields.  As the torpedo streaked towards them, Chang gives an order for impulse power to move out of the way.  As the torpedo looped back at them, Chang's last words are, "...or not to be."

Sulu fires on the exploding Bird of Prey, noting they never even raised their shields.

As Azetbur's speech ended, she was joined by President Ra-ghoratrei and Rear Admiral Smillie. The Assassin smiled as he takes aim with his phaser.

Kirk materializes and runs for the central dais shouting "Mr. President." He knocks over the President just as the Phaser fired. Scottie blasts the assassin, and the conspirators are rounded up. Kirk explains what has happened to Azetbur and makes an elegant speech. They embrace.

After successful negotiations, Azetbur visits Kerla and explains Chang's role in the conspiracy. She tells Kerla that Chang accused him of plotting against her farther, Gorkon. They kiss and make up. {This is not part of the movie.}

On the bridge of the Enterprise the crew it together for the last time. They reminisce and acknowledge the absence of Sulu. His empty chair, a reminder that its most recent occupant, Valeris, now resides in the brig. Sulu joins them on the view screen and they say their good-bys. Starfleet command orders the Enterprise back to be decommissioned, and Spock said, "If I were fully human, I would tell them to go to hell." Jim, reluctant to leave his friends, orders the course and heading, "Second star to the right and straight on till morning."

Critique:

I like the movie with it's familiar theme where Kirk and Crew once again save the Federation.  It's a rabble rousing action adventure with very few slow spots.  And those slower spots it does have add to the movie. 

The book, on the other hand, expands the scope of the story by sprinkling in lots love interests.  It does little to enhance the story while adding lots of bulk to the book.  I would liked to have had more depth added to the conspiracy and the conspirators with more technology sprinkled in.  As it is the technology that was added was inconsistent with the established Star Trek  mythology.   Such as the Enterprise clocking and in several places the ship is ordered to some fractional impulse power using thrusters only. Thrusters, or more correctly maneuvering thrusters, are used for station keeping or slight movement at very slow speeds. i.e. coming out of space dock. Never in combination with impulse power.