In the fictional universe of Star Trek, the Department of Temporal Investigations is an agency of the government of the United Federation of Planets that investigates temporal incursions and attempts to maintain the integrity of the Federation's past. A fictional universe is a cohesive imaginary world that serves as the setting or backdrop for one or (more commonly) multiple works of fiction. ... Main article: Star Trek: The Original Series Star Trek debuted on NBC on September 8, 1966, having aired in Canada some days earlier. ... In the fictional Star Trek universe, the United Federation of Planets is a federation of more than 150 member planets and thousands of colonies, claiming territory in the Alpha and Beta Quadrants of the Milky Way Galaxy. ...

In 2373, two DTI agents traveled to Starbase Deep Space 9 to interview station CO Benjamin Sisko about his crew's accidental trip to 2267 as part of Arne Darvin's attempt to assassinate James T. Kirk. ("Trials and Tribble-ations" [DS9]). A starbase is usually portrayed as a facility strategically positioned in space used to repair and re-supply starships. ... Space station Star Trek: Deep Space Nine (ST:DS9 or STDS9 or DS9 for short) is a science fiction television series produced by Paramount and set in the Star Trek universe. ... Benjamin Lafayette Sisko (Born 2332, New Orleans, Louisiana) is a character in the fictional Star Trek universe, the star of the Star Trek spinoff series Star Trek: Deep Space Nine. ... The 23rd century (Gregorian Calendar) comprises the years 2201-2300. ... James Tiberius Kirk (William Shatner) was captain of two Starships Enterprise (NCC-1701 and NCC-1701-A) in the fictional Star Trek universe. ...

It is unclear whether or not operatives can actually travel in time; the only time they have been seen is in an episode of Star Trek: Deep Space Nine. The fact that Temporal Investigations knew about the trip at all does suggest they may have a means to detect time travel, perhaps involving the Guardian of Forever; on the other hand, it's just as likely that Sisko and Co. dutifully reported their experiences to the Department.

By the 29th century, the Federation Starfleet has taken over at least part of the function of Temporal Investigations and operates a fleet of ships which can travel in time and protect the timeline from detectable changes. (Star Trek: Voyager episodes "Relativity" and "Future's End") Space station Star Trek: Deep Space Nine (ST:DS9 or STDS9 or DS9 for short) is a science fiction television series produced by Paramount and set in the Star Trek universe. ... The Guardian of Forever is a time portal portrayed in the universe of Star Trek. ... The 29th century (Gregorian Calendar) comprises,for some, the years 2801-2900. ... Starfleet Command In the Star Trek fictional universe, Starfleet is the defense, research, diplomacy, and exploration force of the United Federation of Planets. ... The starship Voyager (NCC-74656), an Intrepid-class starship. ... Relativity is a fifth season episode of Star Trek: Voyager, first broadcast on May 12, 1999. ...

See also

• Temporal Cold War

The Temporal Cold War is a fictional conflict waged throughout history, notably during the 3rd and early 4th millennia CE in the Star Trek universe. ...

External links

• Temporal Investigations article at Memory Alpha, a Star Trek wiki