Story arcs

Template:Realworld Story arcs are stories in Star Trek that are told over the course of multiple episodes. They are not simply two-parters or recurring characters and themes, but rather plots that are interwoven with other arcs and plot threads. An example of this is DS9's introduction of the Dominion and the eventual Dominion War. Story arcs often take precedence over other plot elements and consume a series for several consecutive episodes, but in many cases (such as the Dominion War) they may take a back seat and re-enter the picture later on.

Prior to DS9, story arcs were a relatively minor part of the Star Trek universe. TOS and TNG both largely restored the status quo ante at the end of each episode, and even two-part episodes were somewhat rare. This changed due to the stationary nature of space station Deep Space 9, which did not simply move on to the next adventure each week; characters' actions had lasting consequences, and the events of one episode directly influenced the next.

VOY took the idea of the story arc in a different direction by setting itself aboard a starship as per the traditional Trek formula but stranding its crew in the distant Delta Quadrant. This both enhanced and reduced the prevalence of story arcs; while alien races such as the Kazon and Borg appeared in multiple episodes, the show was hampered by its very nature: the object was to leave familiar elements behind, which meant each plot thread had a limited life span.

Feature-length episodes

These episodes are originally broadcast in two hours, as opposed to the standard one hour. After their original run, feature length episodes are re-cut as two part episodes (see below). They include:

• TNG:
  • "Encounter at Farpoint"
  • "All Good Things..."
• DS9:
  • "Emissary"
  • "The Way of the Warrior"
  • "What You Leave Behind"
• VOY:
  • "Caretaker"
  • "Dark Frontier"
  • "Flesh and Blood"
  • "Endgame"
• ENT:
  • "Broken Bow"

Two-part episodes

These episodes air separately, but tell the same story. It is typical for the first part to end with the line "To Be Continued...". They are frequently used to end and begin seasons. Two-part episodes include:

• TOS:
  • "The Menagerie, Part I" and "The Menagerie, Part II"
• TNG:
  • "The Best of Both Worlds" and "The Best of Both Worlds, Part II"
  • "Redemption" and "Redemption II"
  • "Unification I" and "Unification II"
  • "Time's Arrow" and "Time's Arrow, Part II"
  • "Chain of Command, Part I" and "Chain of Command, Part II"
  • "Birthright, Part I" and "Birthright, Part II"
  • "Descent" and "Descent, Part II"
  • "Gambit, Part I" and "Gambit, Part II"
• DS9:
  • "The Maquis, Part I" and "The Maquis, Part II"
  • "The Search, Part I" and "The Search, Part II" (see below)
  • "Past Tense, Part I" and "Past Tense, Part II"
  • "Improbable Cause" and "The Die is Cast"
  • "Homefront" and "Paradise Lost"
  • "In Purgatory's Shadow" and "By Inferno's Light"
  • "Favor the Bold" and "Sacrifice of Angels" (see below)
  • "Image in the Sand" and "Shadows and Symbols" (see below)
• VOY:
  • "Basics, Part I" and "Basics, Part II"
  • "Future's End" and "Future's End, Part II"
  • "Year of Hell" and "Year of Hell, Part II"
  • "The Killing Game" and "The Killing Game, Part II"
  • "Equinox" and "Equinox, Part II"
  • "Unimatrix Zero" and "Unimatrix Zero, Part II"
  • "Workforce" and "Workforce, Part II"
• ENT:
  • "Shockwave" and "Shockwave, Part II"
  • "Storm Front" and "Storm Front, Part II"
  • "Affliction" and "Divergence"
  • "In a Mirror, Darkly" and "In a Mirror, Darkly, Part II"
  • "Demons" and "Terra Prime"

Three-part episodes

Three consecutive episodes that air separately, but tell the same story.

• TNG:
  • "The Best of Both Worlds", "The Best of Both Worlds, Part II", "Family"
• DS9:
  • "The Homecoming", "The Circle", and "The Siege"
  • "The Jem'Hadar", "The Search, Part I", and "The Search, Part II"
  • "Tears of the Prophets", "Image in the Sand", and "Shadows and Symbols"
• VOY:
  • "Scorpion", "Scorpion, Part II", and "The Gift"
• ENT:
  • "Borderland", "Cold Station 12", and "The Augments"
  • "The Forge", "Awakening", and "Kir'Shara"
  • "Babel One", "United", and "The Aenar"

Multi-episode arcs

• TNG:
  • Q and the Enterprise
    • "Encounter at Farpoint"
    • "Hide and Q"
    • "Q Who"
    • "Deja Q"
    • "Qpid"
    • "True Q"
    • "Tapestry"
    • "All Good Things..."
  • Worf vs. Duras
    • "Sins of the Father"
    • "Reunion"
    • "The Mind's Eye"
    • "Redemption"
    • "Redemption II"
    • DS9: "The Sword of Kahless"
  • Sela
    • "Yesterday's Enterprise"
    • "The Mind's Eye"
    • "Redemption"
    • "Redemption II"
    • "Unification I"
    • "Unification II"
• DS9:
  • Changeling infiltration
    • "The Die is Cast"
    • "The Adversary"
    • "The Way of the Warrior"
    • "Homefront"
    • "Paradise Lost"
    • "Apocalypse Rising"
    • "In Purgatory's Shadow"
    • "By Inferno's Light"
  • The Beginning of the Dominion War
    • "In the Cards"
    • "Call to Arms"
    • "A Time to Stand"
    • "Rocks and Shoals"
    • "Sons and Daughters"
    • "Behind the Lines"
    • "Favor the Bold"
    • "Sacrifice of Angels"
  • The Ending of the Dominion War
    • "Penumbra"
    • "'Til Death Do Us Part"
    • "Strange Bedfellows"
    • "The Changing Face of Evil"
    • "When It Rains..."
    • "Tacking Into the Wind"
    • "Extreme Measures"
    • "The Dogs of War"
    • "What You Leave Behind" (feature-length)
• VOY:
  • Seska
    • "State of Flux"
    • "Maneuvers"
    • "Alliances"
    • "Lifesigns"
    • "Investigations"
    • "Basics, Part I"
    • "Basics, Part II"
    • "Worst Case Scenario"
    • "Shattered"
  • Q Civil War
    • "Death Wish"
    • "The Q and the Grey"
    • "Q2"
  • The Hirogen's Hunt
    • "Message in a Bottle"
    • "Hunters"
    • "Prey"
    • "The Killing Game"
    • "The Killing Game, Part II"
    • "Flesh and Blood"
• ENT:
  • Temporal Cold War
    • "Broken Bow"
    • "Cold Front"
    • "Detained"
    • "Two Days and Two Nights"
    • "Shockwave"
    • "Shockwave, Part II"
    • "Future Tense"
    • "The Expanse"
    • "Carpenter Street"
    • "Azati Prime"
    • "Zero Hour"
    • "Storm Front"
    • "Storm Front, Part II"
  • Search for the Xindi superweapon
    • "The Expanse"
    • The entire third season of Enterprise
    • "Storm Front"
    • "Storm Front, Part II"

Non-consecutive arcs

• The Talosians
  • TOS: "The Cage", "The Menagerie, Part I", "The Menagerie, Part II"
• Harry Mudd
  • TOS: "Mudd's Women", "I, Mudd", and TAS: "Mudd's Passion"
• Polywater intoxication
  • TOS: "The Naked Time" and TNG: "The Naked Now"
• Shore Leave Planet
  • TOS: "Shore Leave" and TAS: "Once Upon a Planet"
• Kor
  • TOS: "Errand of Mercy", TAS: "The Time Trap", DS9: "Blood Oath", "The Sword of Kahless", "Once More Unto the Breach"
• Cyrano Jones and his tribbles
  • TOS: "The Trouble with Tribbles" and TAS: "More Tribbles, More Troubles"

DS9 revisits the TOS episode in DS9: "Trials and Tribble-ations", however no significant historical events are altered.

• Arne Darvin
  • TOS: "The Trouble with Tribbles" and DS9: "Trials and Tribble-ations"
• Khan Noonien Singh
  • TOS: "Space Seed" and Star Trek II: The Wrath of Khan
• DaiMon Bok and his revenge attempts on Picard
  • TNG: "The Battle" and "Bloodlines"
• The Traveler and his interactions with Wesley Crusher
  • TNG: "Where No One Has Gone Before", "Remember Me", "Journey's End"
• The Crystalline Entity
  • TNG: "Datalore" and "Silicon Avatar"
• Alien neural parasites infiltrate Starfleet Command
  • TNG: "Coming of Age" and "Conspiracy"

The follow-on investigation of the parasite infiltration is mentioned in "The Drumhead"

• Professor James Moriarty
  • TNG: "Elementary, Dear Data" and "Ship in a Bottle"
• Arridor and Kol
  • TNG: "The Price" and VOY: "False Profits"
• Vash and her relationship with Jean-Luc Picard and Q
  • TNG: "Captain's Holiday" and "Qpid", and DS9: "Q-Less"
• Thomas Riker
  • TNG: "Second Chances" and DS9: "Defiant"
• Riker and the Pegasus
  • TNG: "The Pegasus" and ENT: "These Are the Voyages..."
• Borg and First Contact (the Borg's involvement with Earth's first contact in 2063 and the repercussions which followed)
  • Star Trek: First Contact, ENT: "Regeneration", and TNG: "Q Who"
• The Dominion's threat to the Alpha and Beta Quadrants
  • DS9: "The Jem'Hadar" through "What You Leave Behind"
• Anti-alien sentiments on Bajor
  • DS9: "Emissary", "Past Prologue", "In the Hands of the Prophets", "The Homecoming", "The Circle", and "The Siege"
• Bajor's entry into the Federation
  • DS9 Season 1, 2, 3 and through 4, DS9: "Rapture"
• The Maquis struggle for self-determination
  • TNG: "Preemptive Strike", DS9: "The Maquis, Part I", "The Maquis, Part II"; various episodes until "Blaze of Glory"
• Kira and Odo
  • DS9: "Heart of Stone", "Crossfire", "Children of Time", "Call to Arms", "His Way", "Chimera", "What You Leave Behind"
• Kira and Dukat
  • DS9: "The Maquis, Part II", "Civil Defense", "Indiscretion", "Return to Grace", "In Purgatory's Shadow", "A Time to Stand", "Sons and Daughters", "Wrongs Darker Than Death or Night", and "Covenant"
• Eddington vs. Sisko
  • DS9: "For the Cause", "For the Uniform", "Blaze of Glory"
• Quark and Grilka
  • DS9: "The House of Quark", "Looking for par'Mach in All the Wrong Places"
• O'Brien and Liam Bilby
  • DS9: "Honor Among Thieves", "Prodigal Daughter"
• Federation-Dominion Cold War
  • DS9: "The Die is Cast", "The Adversary", DS9 Season 4 (esp. DS9: "The Way of the Warrior", "Homefront", "Paradise Lost"), DS9: "Apocalypse Rising", "In Purgatory's Shadow", "By Inferno's Light"
• The Hirogen and holographic technology
  • VOY: "The Killing Game", "The Killing Game, Part II", "Flesh and Blood"
• The Silver Blood
  • VOY: "Demon", "Course: Oblivion"
• Q Continuum
  • VOY: "Death Wish", "The Q and the Grey", "Q2"
• Fair Haven
  • VOY: "Fair Haven", "Spirit Folk"
• Barclay and the Pathfinder Project
  • VOY: "Pathfinder", "Life Line", "Inside Man", "Author, Author"
• Temporal Cold War
  • ENT: "Broken Bow", "Cold Front", "Shockwave", "Shockwave, Part II", "Future Tense", "The Expanse", "Storm Front, Part II"
• Andorians vs. Vulcans
  • ENT: "The Andorian Incident", "Shadows of P'Jem", "Cease Fire", "The Forge", "Awakening", and "Kir'Shara"
• The Klingon trial of Jonathan Archer
  • ENT: "Judgment", "Bounty", "The Expanse"
• Augments and Khan Noonien Singh
  • ENT: "Borderland", "Cold Station 12", "The Augments", TOS: "Space Seed" and Star Trek II: The Wrath of Khan
• Xenophobic Humans
  • ENT: "Home", "Demons", "Terra Prime"
• Lore
  • TNG: "Datalore", "Brothers", "Descent", "Descent, Part II"

Section 31 episodes

22nd century episodes

• ENT:
  • "Affliction"
  • "Divergence"
  • "Demons"
  • "Terra Prime"

24th century episodes

• DS9:
  • "Inquisition"
  • "Inter Arma Enim Silent Leges"
  • "Extreme Measures"

"The Enterprise Incident", Star Trek VI: The Undiscovered Country, and "The Pegasus" have often been referenced in non-canon literature as having Section 31 involvement. "These Are the Voyages..." also references a "secret section of Starfleet Security", which may be a reference to Section 31.

Mirror universe episodes

See also: Mirror universe

• TOS:
  • "Mirror, Mirror"
  • "The Tholian Web" (related to "In a Mirror, Darkly" and "In a Mirror, Darkly, Part II")
• DS9:
  • "Crossover"
  • "Through the Looking Glass"
  • "Shattered Mirror"
  • "Resurrection"
  • "The Emperor's New Cloak"
• ENT:
  • "In a Mirror, Darkly"
  • "In a Mirror, Darkly, Part II"