Trials and Tribble-ations
"Trials and Tribble-ations" is the Star Trek: Deep Space Nine sequel to "The Trouble With Tribbles", an episode of the original Star Trek. In this episode, Captain Benjamin Sisko and his crew must travel back in time to prevent disgraced Klingon spy Arne Darvin, under the guise of human merchant Barry Waddle, from altering history and changing the events of "The Trouble with Tribbles" so that they end in Kirk's death. In their travels to the past, Jadzia Dax reminisces about her previous host's travels with Kirk, and Dr. Bashir lusts after a woman who, in a joke reminiscent of Futurama, may be his great-grandmother.
Then-advanced digital computer modeling was used to work modern actors into the 1960s-era film frames from the original episode.
- "Trials and Tribble-ations" at Memory Alpha Star Trek wiki