Overview
The episode sees the crew of DS9 travel into their past, and encounter the events of the original series episode "The Trouble With Tribbles". The crew interact with events of that episode, meeting James T. Kirk and visiting the original Enterprise by means of modern special effects technology which allows the DS9 actors to be inserted into footage from the original episode.
Agents Dulmer and Lucsly (anagrams for The X-Files agents Mulder and Scully), from the Department of Temporal Investigations, interrogate Captain Sisko of Deep Space Nine as to why he and his crew aboard the USS Defiant traveled to the year 2268, to Deep Space Station K-7. While the crew was there, they foiled an assassination attempt on Captain James T. Kirk of the USS Enterprise by the resentful Klingon ex-agent Arne Darvin.
Read more about this topic: Trials And Tribble-ations