An explosion of their key mining facility, Praxis, throws the Klingon Empire into a horrible economic downturn. It has been estimated they have 50 years before their ozone layer is depleted and they all die. Due to their high military spending, the Klingons are unable to deal with this disaster and have no choice but to make peace with the Federation and end many years of hostility. The Chancellor of the Klingon High Council makes plans to go to Earth for the first steps of peace and Captain Spock vouches for the Enterprise-A crew to escort the Chancellor's ship. Peace plans don't go as planned, when Starfleet officers beam over to the Chancellor ship and assassinate the Chancellor. Also, according to the Enterprise-A's computer databanks, they opened fired on the Chancellor's ship even though all torpedos are accounted for. Kirk and McCoy are arrested for the assassination of the Chancellor and sent to Rura Penthe, a snowy prison camp. Meanwhile, Spock and the rest of the crew try to unravel the mystery of who really fired on the Chancellor's ship and assassinated the Chancellor. Will Kirk and McCoy escape Rura Penthe? Can the Enterprise-A crew save the galaxy from war?

William Shatner - Captain Kirk

Leonard Nimoy - Captain Spock

DeForest Kelley - Dr. Leonard McCoy

James Doohan - Capt. Scott

Walter Koenig - Cmdr. Chekov

Nichelle Nichols - Cmdr. Uhura

George Takei - Capt. Sulu

Kim Cattrall - Lt. Valeris

Mark Lenard - Ambassador Sarek

Grace Lee Whitney - Cmdr. Rand

Brock Peters - Adm. Cartwright

Leon Russom - Starfleet Commander in Chief

Kurtwood Smith - Federation president

Christopher Plummer - Gen. Chang

Rosanna DeSoto - Azetbur

David Warner - Chancellor Gorkon

John Schuck - Klingon ambassador

Michael Dorn - Col. Worf

Paul Rossilli - Brig. Gen. Kerla

Robert Easton - Klingon judge

Clifford Shegog - Klingon officer

William Morgan Sheppard - Klingon commander

Brett Porter - Gen. Stex

Jeremy Roberts - Lt. Dmitri Valtane

Michael Bofshever - Excelsior engineer

Angelo Tiffe - Excelsior navigator

Boris Lee Krutonog - Helmsman Lojur

Christian Slater - Ens. Slater

Iman - Martia

Tom Morga - The Brute

Todd Bryant - Klingon translator

John Bloom - Behemoth alien

Jim Boeke - Klingon general 1

Carlos Cestero - Munitions man

Edward Clements - Young crewman

Katie Johnston - Martia as a child

Doug Engalla - Prisoner at Rura Penthe

Matthias Hues - Klingon general 2

Darryl Henriques - Ambassador Nanclus

David Orange - Sleepy Klingon

Judy Levitt - Military aide

Shakti - ADC

Michael Snyder - Crewman Dax

Rene Auberjonois - Col. West

Douglas Dunning - Klingon

Alan Marcus - Man who Killed Klingons

Eric A. Stillwell - Extra

J.D. Walters - Klingon

The subtitle, "The Undiscovered Country," comes from Hamlet's famous "To be or not to be" soliloquy, as do many of General Chang's quotes.

The welcome speech that Kirk, McCoy, and the others receive on arriving on Rura Penthe is an homage to the speech made by Colonel Saito to the British POW's in The Bridge on the River Kwai.

The name of the prison planet, Rura Penthe, is a reference to 20,000 Leagues Under the Sea. It is the name of the slave labor camp that inspired Captain Nemo's rage against society and that was the location of his death.

Spock tells the crew, "An ancestor of mine maintained that if you eliminate the impossible, whatever remains, however improbable, must be the solution." The "ancestor" Spock quotes is Sherlock Holmes, another fictional character well-versed in logic. Leonard Nimoy and co-star 'Plummer, Christopher' have both played Holmes on stage and screen. Also, director Nicholas Meyer is the author of several Sherlock Holmes novels, including "The Seven Per-cent Solution," considered by many to be the best Sherlock Holmes story not written by Sir Arthur Conan Doyle.

William Shatner was distressed when he saw how wide his bottom was in the scene where he walks across the bridge (away from the camera). He had them airbrush the entire scene to make his butt look narrower.

General Chang's eyepatch has three bolts that go into the skull. They all have the Klingon insignia engraved on them.

Frankie and Johnny was being filmed in the same studio, and required Al Pacino to have a surprised expression on his face after opening a door. Director Garry Marshall arranged for Kirk and Spock be on the other side of the door that Pacino opened.

After filming was through one day nearing the end of production, Kim Cattrall posed nude for some steamy photos on the bridge set.

Shatner originally wanted Sulu not to command a starship, but producers overrode his wishes.

An allegory about the fall of Soviet Communism. When Klingon General Chang demands that Kirk answer a question without waiting for the translation, it is an allusion to the real-life exchange at the United Nations between U.S. Ambassador Adlai Stevenson and Soviet Ambassador Valerian Zorin during the 1962 Cuban missile crisis.

The character of Dax in this film (a young crewmember questioned during the search for incriminating evidence) is no relation to the character of Dax from "Star Trek: Deep Space Nine". Star Trek: Deep Space Nine's Dax would, at the time of Star Trek VI, be in the persona of Curzon Dax, a Federation ambassador, which is clearly not the case for ST 6's Dax. The name was a coincidence.

Many of the sets were sets from Star Trek: The Next Generation, redressed to be the Enterprise-A. The Enterprise-A corridors, sickbay, transporter room, dining room, and engineering were all reused. Also, the Federation President's office is the set of "Ten Forward". One of the sets from Next Generation had a series of ships named Star Trek: Enterprise carved into it; this set feature was damaged during the filming of "Undiscovered Country," when the Enterprise was being bombarded by Chang, and no longer appeared in Next Generation episodes filmed after that point.

When the Klingons return to their ship after the dinner on the Enterprise, Chang speaks a Klingon phrase into his communicator (without English subtitles). Chang says "daHmacheH" which, in English, means "Ready to return now."

Nichelle Nichols objected to the scene in which the crew desperately searches through old printed Klingonese translation dictionaries in order to speak the language without the standard universal translator being used. It seemed more logical to her that Uhura, being the ship's chief communications officer, would know the language of the Federation's main enemy, or at least have the appropriate information in the computer. However, director Nicholas Meyer bluntly overruled her.

Gene Roddenberry died within 48 hours of viewing the film. It was later dedicated to the memory of Gene Roddenberry.

In 1996, Star Trek: Voyager revisited the events on the Excelsior that took place during this film, and reunited Excelsior crew cast members George Takei (Capt. Sulu), Grace Lee Whitney (Rand), and 'Roberts, Jeremy' (Valtrane) in an episode entitled "Flashback." The episode also featured an appearance by classic Star Trek Klingon Michael Ansara as Kang and reused the effects shot of the Excelsior being struck by a shock wave; and intregrated the Voyager character of Tuvok in the events.

Michael Dorn plays Colonel Worf in this film, and Lieutenant Worf in Star Trek: The Next Generation. Colonel Worf is meant to be the grandfather of Lieutenant Worf.

Plummer, Christopher' asked that he be allowed to wear less "severe" Klingon makeup for his role as General Chang.

Colonel West, the Starfleet Marine officer who conducts the Operation Retrieve briefing, was meant to be a reference to Colonel Oliver North, the real-life U.S. Marine accused of shredding confidential documents associated with the Iran-Contra scandal of the 1980's.

The film's title was originally intended for Star Trek II: the Wrath of Khan. The first title for Star Trek II was "The Undiscovered Country". It was in reference to Spock's death. It was changed because the executives at Paramount wanted Kahn's name in the title.

The name "Gorkon" is a blending of the names Gorbachev and Lincoln, two of Nicholas Meyer's models for the character of the Klingon chancellor.

Portraits of American president Abraham Lincoln and Vulcan ambassador Sarek are visible in the officers' mess. The first is an idol of Kirk's (from the TV episode The Savage Curtain) and the second is an important figure in Vulcan's history.

The sequence for the explosion of the Klingon bird of prey is the identical footage, frame for frame, used for the explosion of the Klingon bird of prey in "Star Trek: Generations." (The story situations are also very similar in the two movies.)

The Klingon Language Institute, an organization dedicated to the Klingon language as formulated by Marc Okrand, took it upon themselves to translate Shakespeare into Klingon based on David Warner's line about hearing Shakespeare in the original Klingon.

According to the producers, the Klingon blood was purple to avoid an "R" rating. Also, the use of purple blood was to serve as a visual symbol both metaphorical (showing the vast differences between Klingon and Human values and ideals) and literal (showing the differences between our anatomies; slamming home why McCoy could never have saved the Chancellor's life). Klingon blood has always been red in the television series.

The casting director was Mary Jo Slater, mother of Christian Slater. Thus his small role as a Communications Officer aboard the Excelsior.

Kirk makes open references to Star Trek: The Next Generation in his final Captain's Log, first by saying the Enterprise would fall under "the care of a new generation", then by amending "where no man has gone before" in mid-statement to say "where no ONE has gone before", which is the opening prologue to The Next Generation's TV series. The next film, of course, was Star Trek: Generations (1994), which featured predominantly the Next Generation cast. The actors' signatures at the end were supposed to be the characters signatures as they signed the final log.

The Klingon trial concept was originally introduced in a draft script for Star Trek IV - The Voyage Home.

The official Star Trek Chronology suggests this film takes place in the year 2293, or 27 years after the events of the first episodes of the TV series, which the chronology suggests occur in 2266. This is taken from a line by McCoy stating he has served on the Enterprise for 27 years. According to the Chronology, Star Trek VI therefore takes place about six years after the events of Star Trek V, and some 22 years after the events of Star Trek: The Motion Picture.

To be, or not to be" in Klingon is "taH pagh, taH be'".

First Star Trek production to officially establish that Kirk's middle name is Tiberius and Sulu's first name is Hikaru. Tiberius had been mentioned in an episode of the animated Star Trek series, however by this point the cartoon was no longer considered canonical. No first (or last) name is offered for Uhura in this film, which is taken as confirmation of Roddenberry's contention that she has no other name.

Merritt Butrick appears one last time as David Marcus, as a photograph on James T. Kirk's desk. Butrick had died the previous year.

Christopher Plummer's character "General Chang" was originally to have had hair, but as his makeup was being applied for the first time, Plummer liked the bald look and had the makeup technician omit the hair.

Whoopi Goldberg was invited to play her ST:Star Trek: The Next Generation character but declined.

Jack Palance was offered the part Of Chancellor Gorkon but passed because of the dates clashed with City Slickers.

According to Nicholas Meyer, Brock Peters found Admiral Cartwright's words during the briefing scene to be so offensive he needed several takes to get them all out. In a similar vein, Nichelle Nichols refused to utter the joke line "Guess who's coming to dinner?" - an intentional reference to the famous film about racism which is heard prior to the Klingons' visit to Enterprise. The line was instead given to Chekov.

In earlier screenplay drafts, the character of Maltz from Star Trek III - The Search for Spock appeared at the trial as one of Chang's witnesses, answering questions about Kirk's killing of the Klingon crew from that film. The scene was dropped as it was deemed extraneous, and John Larroquette was unavailable to reprise the part.

A sub-plot to this movie was to show that even in the 23rd Century humans haven't totally shed their own bigotry and prejudices. James Doohan had a line about "that Klingon bitch". But Nichell Nichols refused to say the line, in reference to the Klingons, "Yeah, but would you let your daughter marry one of them?" The line was dropped.

Chang is a Thai name meaning "tasteless", a counterpoint to the character's affinity for Shakespeare and fine wine.

The Klingon translating Chang's words into English is Klaa, the renegade captain from the previous film. Though it isn't said in the film, several sources state the character was demoted to translator duty as punishment for his unsanctioned attack on Kirk.

The chorus heard in the background of many scenes, mainly those on Rura Penthe, says "To be, or not to be" in Klingon.

Nicholas Meyer was worried that William Shatner would be upset at some of the lines written for the scene where Martia, disguised as Kirk, fights him. However, Shatner reportedly loved it.

Theatrical trailer features different/additional footage: the wide shots on Rura Penthe show Kirk, McCoy and Martia escaping during daylight while in the film they escape during dusk or dawn the arrival of the president of the federation and Azetbur on Camp Kitomer when the Enterprise is attacked McCoy says "This is fun" when Martia is shot you see a close-up of her, not the wide shot used in the film

The Enterprise traitor was originally written to be Saavik, Spock's trainee from Star Trek - The Wrath of Khan, Star Trek III - The Search for Spock, and Star Trek IV - The Voyage Home lending greater impact to her betrayal. However, neither of the actresses who had played Saavik (Kirstie Alley, Robin Curtis) were available, so the character was rewritten into Valeris, who is played by Kim Cattrall.

Kim Cattrall says that she was allowed to choose the name of her character and decided on "Valeris," integrating "Eris," the name of the Greek goddess of strife and subtly hinting at her character's part in the grand scheme of the movie. This is also the only instance that the naming convention for Vulcans in the Star Trek series was broken (masculine Vulcan names tend to start with the letter "S," and feminine Vulcan names tend to start with "T'").

Continuity error: The clocks in the bridge when Spock is questioning Lt Valeris.

Revealing mistake: When Lt. Valeris reports to Capt. Spock and Scotty in the tunnel, she slides down a pole. She lightly bumps against the angled wall on her way down and the wall moves.

Continuity error: When Sulu is telling Kirk the location of the peace conference, the monitors behind Kirk do not match with the image of Sulu in the main viewscreen.

Continuity error: The position of the Excelsior officer who talks about the location of the Praxis.

Audio/visual unsynchronized: On Rura Penthe, McCoy's lips initially aren't moving when he says, "He's definitely on about something, Jim."

Continuity error: The tea cup on the table before the shockwave hit Sulu's ship.

Continuity error: McCoy's position during fight scene between the two Kirks on the Klingon prison planet.

Continuity error: The direction General Chang is looking before the photon torpedo hits his Bird of Prey.

Continuity error: In the kitchen scene, when Lieutenant Valeris is demonstrating to Commander Pavel Chekov that it is impossible to fire an unauthorized phaser on board a starship, the cook carrying the tray dodges the phaser beam twice.

Revealing mistake: In the locker room scene, the marks on the locker door where the magnetic boots are supposed to go can be seen (Velcro, painted the color of the locker).

Continuity error: Spock's hands after the mind meld with Valeris.

Continuity error: The clock on the bridge is frozen when Chang is talking through the speakers during the battle.

Continuity error: During the battle with Chang, Scotty is wearing his black and white engineer's uniform. But when the crew beams down to stop the assassination, he is wearing the standard red uniform. Then, when they are back on the bridge at the end of the film, he's wearing the engineer's uniform again.

Continuity error: When Mccoy is giving CPR to Chancellor Gorkon, General Chang changes position between shots.

Continuity error: During the trial, the position of Kirk and McCoy changes between shots.

Continuity error: When the Klingons are being beamed aboard for dinner, Scotty changes position between shots.

Continuity error: The name of the character "Uhura" is misspelled "Uhuru" in the end credits.

Crew or equipment visible: When Chang and Kirk finally talk to one another standing in the dining area, a crewmember is reflected in one of the Enterprise's windows on the far right of the picture.

Continuity error: At the beginning of the film, when the Excelsior encounters the energy wave created by the explosion of Praxis, Sulu's hair goes from being neatly groomed to mussed up back to neatly groomed between shots.

Continuity error: When the second torpedo hits Grokon's ship, the clock above the viewscreen on the enterprise reads 01:38. The camera then cuts to Kirk. When we see the viewscreen again, Chang is displayed, but clock above his image reads 01:29.

Audio/visual unsynchronized: When Scotty is reporting that the torpedo bay is "fully loaded" during the initial attack, the audio does not match the movements of his mouth in the reflection in the screen.

Crew or equipment visible: During the assassination scene, after Chancellor Gorkon says "Find Chang!" the shadow of the camera can be seen on the left side of the screen in a shot of some doors opening.

Continuity error: When Spock puts the special detection patch on Kirk's shoulder, it is horizontal. But soon after, on the Klingon battle cruiser, it is vertical.

Continuity error: The recording of Kirk's log entry, heard during the trial, does not exactly match what Kirk says during the actual scene (though it's possible this was intended to be a clue of a conspiracy).

Revealing mistake: When the Klingon vessel loses gravity and the officer's pistol comes out of its holster, the string pulling the weapon free can be seen.

Continuity error: When Kirk and McCoy are arrested, one of the Klingon guards put Kirk's hands into the handcuffs twice.

Audio/visual unsynchronized: In the galley, just as Scotty exits, Spock orders: "Valeris, please inform Starfleet Command that our warp drive is inoperative." Yet Spock's lip movements seem to indicate that the name "Valeris" was dubbed over "Commander Uhura," which would make sense given that the latter is the ship's communications officer and she is standing right there, but was likely changed to match the subsequent dialogue and action: Valeris asks, "A lie?"; Spock replies, "An error"; then Valeris walks away as Spock continues to speak with Uhura.

Continuity error: The special torpedos aboard Captain Sulu's ship at the beginning of the film mysteriously appear on the Enterprise near the end when one is modified to detect the cloaked Klingon ship.

At the beginning of the end credits, the signature of each of the principle cast members is written one by one as a final send off for their characters.

In the end credits, the character of Uhura is misspelled as "Uhuru."

The opening titles shift color - pink, purple, blue, green, and around again.

The network TV version (for NBC) excludes several scenes including the scene where Lt. Valeris mentions that "You men have work" and the scene where Starfleet command presents a retreival plan to the federation president.

The original theatrical release did not include the portion of the scene in the Federation President's office where Col. West outlined his plan to rescue Kirk & McCoy. Also at the climax of the film, the bit where the Klingon assassin is revealed to be none other than Col. West was not included.

The original ending credits, after the sign-off, has a blue/white background with a Starfleet Logo as a watermark. The left side was blue with white lettering, and the right side was white with blue lettering.

Additional inclusions for home video include extra dialog for Spock in the top brass meeting and a scene where Scotty verifies torpedo inventory, Valaris mentions the Chancelor's daughter has succeeded her dead father (she heard it on "the news") and Scotty mentions that the daughter never cried over the death of her father. Spock also mentions that Klingons have no tear ducts.

The Special Collector's Edition DVD includes all the new scenes from the home video releases, and a few new minor changes to certain scenes and effects exclusive to this DVD.

When Martia gets shot, a disruption sound effect is removed to make her scream more apparent.

There is a new wide shot of Scotty reading the blueprints of the Enterprise in the dining hall.

Valeris's interrogation scene has been entirely reedited. There are now close up shots of Kirk and McCoy when they speak their lines instead of being in wide shots. When Spock and Valeris name a particular conspirator, the face of that person briefly appears in a flashback like style.

For the widescreen home video release the matte was opened up a little resulting in an aspect ration of 2:1 instead of 2,35:1. As the film was shot in Super 35 this means (in this case) that you actually see more of the picture than in theaters.