The 30th anniversary of Star Trek was celebrated across the whole franchise. The Next Generation crew starred in their finest movie adventure, First Contact, and George Takei guest starred as Sulu in the Voyager episode Flashback. But as far as I'm concerned the episode produced for Deep Space Nine remains the finest anniversary celebration (and also my favourite time travel adventure from any Star Trek series) ever produced by any long running series.
Broadcast on November 4th 1996, Trials and Tribble-ations saw the crew of DS9 seamlessly integrated into the 1967 episode The Trouble with Tribbles, it even saw Charlie Brill reprising the roll he played in the original episode, now as the older Arne Darvin. There are several scenes where the two crews interact which were so well done that if I didn't know better I might've believed the original actors were actually on set.
Originally it looked like the anniversary would be celebrated with the DS9 crew traveling to the planet visited in The Original Series episode A Piece of the Action. Then consideration was given to having a different original cast member appear in the series, but as this had been done several times (and with Voyager doing just that again) it was felt that this would not be special enough. René Echevarria came up with the idea of a time travel adventure, which at first was deemed to be too expensive. Ronald D Moore thought it could work though, and half-jokingly suggested revisiting The Trouble with Tribbles and inserting the DS9 crew to resolve the question of why a constant stream of tribbles kept hitting Kirk in the head.
Producers Rick Berman and Ira Steven Behr both liked the idea of an episode built around a previous adventure but felt it couldn't be achieved successfully, so Visual Effects supervisor Gary Hutzel created test footage using the same technique seen in Forest Gump. Hutzel used the famous bar fight scene, which when screened for the production team they all just assumed it was the 'before' footage and waited for the new version. Not one of them spotted that an additional security officer had been digitally inserted. Once Hutzel revealed this to them the episode was green lit. That scene would go on to be further adapted for the finished story...
It was clear that this episode was going to be an expensive one to produce, an awful lot of work would be undertaken to pull it off so successfully. So that the new finished product would be up to the broadcasting standards of the time, The Trouble With Tribbles became the first classic adventure to be digitally remastered. Some of the original costumes, sets and props were discovered and utilised, but the majority had to be reproduced. There would also need to be residual payments to the cast of The Original Series, leading to a budget of $3million being allocated for the episode. Behr later commented that for its time it was "probably the most expensive hour of episodic TV ever produced".
The writer of The Trouble With Tribbles, David Gerrold, was credited on the episode (and was even cast as an extra), with the final story written by Behr, Hans Beimler & Robert Hewitt Wolfe, and the teleplay by Moore and Echevarria. What they, and everyone involved in the production created is nothing short of a masterpiece.
The Department Of Temporal Investigations Arrives at Deep Space Nine, the agents are named Dulmer and Lucsly - anagrams of Mulder and Scully from The X-Files. They are investigating what happened when Captain Sisko escorted a 'human' named Arne Darvin back to Federation space. Sisko wearily explains that during the trip the Orb Of Time was aboard the Defiant, and Darvin had used it to transport them and ship back to Space Station K7. Sitting there in space was the USS Enterprise NCC1701.
Arne Darvin had one motive, to kill Captain Kirk who was aboard the station. After changing into the uniforms of the time Sisko, Dax, Bashir and O'Brien beam over to the Enterprise whilst Odo and Worf head to the station to search for Darvin. Whilst looking for him they must be careful to keep any interaction with the crew of the Enterprise to a minimum to avoid contaminating the time line. This goes fairly well until Bashir and O'Brien meet up with Odo and Worf and end up in that bar brawl! When they finally catch Darvin they learn that he was planning to kill Kirk and alter his own timeline in revenge for Kirk ruining his life all those years ago. Darvin has planted a bomb in a tribble, which the DS9 crew race to find.
Trials and Tribble-ations nicely dealt with the fact that the appearance of the Klingon's has changed somewhat since The Original Series, and also passes comment on the changing Star Fleet fashions. It's packed full of fantastic moments that play to the strengths of both casts, not least of which when Dax catches Captain Kirk's eye. Then there's that amazing final scene where the two Captains meet - which actually utilised footage from The Original Series episode, Mirror, Mirror.
Twenty years on it still remains an impressive piece of television, one which was produced with as much love, care and attention to detail as any fan could ever wish for.