List of Star Trek: Enterprise Episodes - Story Arcs

Story Arcs

Star Trek: Enterprise relied upon story arcs more often than previous Star Trek series, with the exception of Deep Space Nine.

The first two seasons had only two story arcs which re-emerged sporadically, while the entire third season was a single arc that also included episodes from the second and fourth seasons. Beginning with the fourth season, the format of the series was altered so that the season featured a number of two- and three-episode arcs.

• ^Temporal Cold War An unidentified force from the 29th century is attempting to disrupt history through a Temporal Cold War. These episodes involve a time traveller from the 30th century, Daniels, who works with Archer and his crew to make sure history is not changed. The Xindi arc (see below), which also involves time travel, is sometimes seen as an offshoot of this.
• ^Xindi A mysterious space probe attacks Earth, killing 7 million people. After receiving information from individuals involved in the Temporal Cold War as to the origin of the weapon, the Enterprise NX-01 is assigned to enter a dangerous region of space to track down those responsible and prevent further attacks on Earth. This arc spanned the entire third season and also overlapped briefly into both the second and fourth seasons. The fourth season in particular sees Archer and his crew dealing with the fallout from the Xindi mission.
• ^Vulcan vs. Andoria These episodes chronicle the tensions existing between Vulcans and Andorians, two races that eventually put aside their differences and ally with Earth to form the United Federation of Planets. This arc intersects with the "Vulcan Reformation" arc, below.
• ^Risa A loosely knit arc from the end of the first season sees Enterprise heading for the pleasure planet, Risa, but encountering detours along the way.
• ^Fugitive from the Klingons This second season arc sees Captain Archer pursued by Klingon forces for alleged violations of Klingon law.
• ^Augments Genetically engineered humans created in the 20th century and nurtured by a brilliant scientist hijack a Klingon vessel and attempt to rescue their adopted "father." Six months later, attempts by Klingons to create their own genetically engineered race result in a virus that kills millions of Klingons and changes their appearance.
• ^Vulcan Reformation Vulcan undergoes an upheaval as followers of Surak's principles try to overthrow the current government which is being secretly manipulated by the Romulans.
• ^Romulan drone ships The Romulans use the mental abilities of an Andorian race called the Aenar to control a series of prototype, remote-controlled vessels designed to spark a war between humans, Vulcans, Andorians, and Tellarites.
• ^Terra Prime These episodes follow the early steps leading toward the creation of the United Federation of Planets. The arc incorporates elements of the Vulcan vs. Andoria arc, the Vulcan Reformation arc, and the Xindi arc.
• ^Section 31 Section 31 is introduced to Enterprise during the Klingon Augments and Terra Prime story lines.
• ^Trip and T'Pol This arc details the evolving relationship between Trip Tucker and T'Pol. Many Xindi arc episodes touched on the Trip/T'Pol arc, as did numerous fourth season story lines.