The Destruction of the USS Odyssey, 2370
The Dominion War as depicted in Deep Space Nine will show up a lot here, because, well, it is pretty much the most devastating conflict in the history of the Federation as we know it—rivaled only, really, by the Federation-Klingon War touched upon in Discovery. And yet the first true shots fired in it still sting hardest, even if the casualty count is minor compared to other engagements.
The destruction of the USS Odyssey in the season two episode “The Jem’Hadar” sets the stage for just how bad conflict with the Dominion will go, a faction unlike anything the Federation has tried to engage with before—resulting in the shock moment a Jem’Hadar attack cruiser initiates a suicide run against the Odyssey, after the ship diverted power from its shield systems to weapons in an attempt to score any damage on the vessel at all. Metatextually, the fact the Odyssey was a Galaxy-Class ship—i.e., the same as TNG’s Enterprise-D—represented an even more dire warning to audiences: what was about to go down would be unlike anything Star Trek had ever seen.
