Lol DS9 episode I've never seen.

Trial and Tribble ations.

Time traveler steals the Defiant and goes back in time to the Enterprise with an explosive Tribble. It mixes The Trouble with Tribbles Star Trek episode in with the story line. Putting the original cast on screen with the DS9 cast well done. It was kind of funny. And Tribbles were all over DS9 in the final scene.

The benefits of watching reruns. Catching an episode you haven't seen now and then.