“Trials and Tribble-ations” is episode six of season five of Star Trek: Deep Space Nine.
This episode opens with Sisko being interviewed by agents from Temporal Investigations regarding a recent excursion through time, so the events he is narrating have already happened.
The Defiant went to Cardassia to bring back the Bajoran Orb of Time, which was taken during the occupation, and they also picked up a human merchant. On the way back to DS9, a temporal event sent them years back in time and light years away. This was done by the human – who isn’t actually a human, but a disgraced Klingon spy modified to look like one. When the Defiant arrives, they see the USS Enterprise, NCC-1701 – the first one.
The disgraced spy is Arne Darvin, who appeared in TOS episode “The Trouble with Tribbles” (and is played by the same actor). He wishes to alter the events that lead to his disgrace. There are scenes from the original episode interspersed with new ones, and in some cases the old scenes have been edited to put the new cast in as well – so Julian and O’Brien are dressed-down by Captain Kirk for example.
This episode highlights one of the continuity problems. In the original series, Klingons did not have cranial ridges; this wasn’t introduced until the films. Worf’s statement is simply ‘We do not discuss it with outsiders.’ An actual reason wasn’t given until the Star Trek: Enterpise episodes “Affliction” and “Divergence”. Worf also describes the Klingon Empire’s crusade to exterminate the tribbles.
In the original episode, there was a Klingon ship commanded by a man called Koloth. The actor playing the role of Koloth reprised the role in the DS9 episode “Blood Oath”, although he didn’t appear in this episode.