Past Tense (Star Trek: Deep Space Nine)

"Past Tense" is a two part episode from the third season of science fiction television series Star Trek: Deep Space Nine, the 57th and 58th episodes overall and the last episode to air before the premiere of its spinoff, Star Trek: Voyager. It is also the first episode of Star Trek: Deep Space Nine to not feature any scenes on the DS9 space station, except for the opening credits. In the episode, a transporter anomaly accidentally sends Commander Sisko, Dr. Bashir, and Jadzia Dax back in time to a pivotal moment in Earth's history. The episode received critical acclaim for analyzing U. S. social issues in a science fiction context, but also for addressing various societal issues such as homelessness, poverty, and technology.

This installment of the Star Trek science fiction television show Star Trek: Deep Space Nine aired in two approximately 45 minute episodes on syndicated television in the United States. Another inspiration for the episode were the writer's experiences with homeless people in California. According to the DVD commentary, as this episode was finishing production an article appeared in the Los Angeles Times describing a proposal by the then mayor, Richard Riordan, to create fenced in "havens" for the city's homeless, to make downtown Los Angeles more desirable for business.

In 2015, Geek. com recommended this episode as "essential watching" for their abbreviated Star Trek: Deep Space Nine binge watching guide. SyFy ranked "Past Tense" as the seventh best time travel plot in Star Trek, in 2016. In 2016, The Hollywood Reporter rated "Past Tense" (Parts I & II) the 47th best television episode of all Star Trek franchise television prior to Star Trek: Discovery, including live action and The Animated Series but not counting the movies. Between 1966 and 2005, there were about 726 episodes of Star Trek television. Ars Technica in 2016, pointed out "Past Tense" as example of how the series had good stories and is "beacon of hope for people living in dark times." They praise the "dogged Utopianism" and note how the characters try to help the poor. In 2016, Empire ranked this the 39th best out of the top 50 episodes of the 700 plus Star Trek television episodes. The Atlantic reviewed "Past Tense" of Star Trek: Deep Space Nine in 2017, suggesting it was the "most political episode" of all Star Trek. They note that in the two part episode Benjamin Sisko travels back in time to early 21st century Earth aboard the USS Defiant spacecraft. They show this is used as a plot device to explore America's issues with racism, violence, and "apathy toward human suffering". In 2018, Vulture rated the pair of "Past Tense" episodes as the 15th best episodes of Star Trek: Deep Space Nine. In 2018, Comic Book Resources ranked the "Past Tense" pair as the 20th best episodic saga of Star Trek overall. In 2020, Den of Geek listed "Past Tense" as one of the best stories of Star Trek: Deep Space Nine. In 2020, SciFiNow ranked this one of the top ten episodes of Star Trek: Deep Space Nine. In 2020, The West Wing Thing, a podcast that normally discusses episodes of the political drama The West Wing had a one off episode where the hosts Dave Anthony and Josh Olson renamed their show The Star Trek Thing and discussed "Past Tense, Part I" and "Past Tense, Part II" instead of a West Wing episode because the duo considered "The Long Goodbye", which was The West Wing episode they planned to discuss that week, so boring to watch that they felt it wasn't talking about on their podcast and decided to skip it and just do "Past Tense" instead. Despite the fact the podcast episode was about "Past Tense" and not "The Long Goodbye", the latter was used as the title for that week's episode. In 2021, Vox compared the vision of the future 2024 San Francisco presented in "Past Tense" with the state of some of the issues touched upon in the episode, such as poverty, riots, and technology. The two parts of the episode were released on VHS tape also by Paramount Home Video

The episode was also released on June 3, 2003, in North America as part of the season 3 DVD box set. This episode was released in 2017 on DVD with the complete series box set, which had 176 episodes on 48 discs.