Memory Alpha
Memory Alpha
Real world article
(written from a production point of view)
Deep Space Nine - Final Chapter

The promotional logo for DS9's "final chapter" story arc

Story arcs are story lines 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 Star Trek: Deep Space Nine'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. Star Trek: The Original Series and Star Trek: The Next Generation 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. At the time, Ira Steven Behr had to fight with Viacom over making the show so serialized. [1]

Star Trek: Voyager 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.

Star Trek: Enterprise, like DS9 before it, often relied on story arcs such as the Temporal Cold War and the Xindi arc that took up the entire third season. By the show's fourth season, Enterprise wrapped up these story arcs and instead refocused on the show's prequel concept with a series of "mini arcs." Most season four episodes are two- or three-part story lines, with few stand-alone episodes.

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), but are usually released in their original broadcast format as a single episode. They include:

"The Killing Game" and "The Killing Game, Part II" aired on the same night in their premiere in the United States but were not edited into a single episode. A feature-length version was broadcast by the BBC on its first airing on 5 September 1999, and formed part of the UK VHS release Star Trek: Voyager - Movies.

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:

Notably, DIS Season 3 was bookended by episodes titled "That Hope Is You, Part 1" and "That Hope Is You, Part 2", though the two were not a single "episode" composed of consecutive episodes in the same series. That season also featured "Unification III" despite "Unification II" being an episode of TNG Season 5.

Similarly, "Crisis Point 2: Paradoxus" also served as a sequel to "Crisis Point" but did not immediately follow that episode.

Three-part episodes[]

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

Multi-episode arcs[]

Multi-episode arcs tell a continuing story and are spread out through several different episodes throughout one or multiple seasons.

The Next Generation[]

Deep Space Nine[]

DS9's "The Final Chapter" is the only story arc given any official titling in on-screen promotional advertisements, presumably because these episodes not only ended the Dominion War, but brought the entire series to a conclusion. It appeared only in commercial previews for the final nine episodes, listed above.





Lower Decks[]


Subject arcs[]

Section 31[]

22nd century episodes

23rd century episodes

24th century episodes

"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 is often retconned into a reference to Section 31.

See also: Section 31 episodes

The mirror universe[]

The alternate reality[]


Q-related episodes

See also: Q episodes

Multi-series arcs[]

Starting in...

The Original Series[]

The Next Generation[]

Deep Space Nine[]

Short Treks[]