10 Darkest Star Trek Moments That You've Never Seen
1. The Setlik III Massacre
The Massacre on Setlik III was disturbing enough to haunt the hearts of its survivors for decades to come. Though we would see Miles O'Brien deal with the fallout in both The Wounded and Tribunal, we do know that it was horrific enough to inspire a starship captain to abandon the Prime Directive.
The first Cardassian wars were skirmishes when one considers them against the Dominion War of the 2370s, yet theirs was a Union that was highly skilled at visiting death and destruction when needed. Setlik III was, by all accounts, one of the smaller engagements of the wars, yet Benjamin Maxwell was unable to put it behind him.
Even O'Brien struggled with it, years later. As he sat across from a Cardassian soldier who was trying to make small-talk, it was all O'Brien could do not to show the man his hatred. Still, as O'Brien says - it wasn't the Cardassian soldier he hated, it was what he became in spite of that soldier and others like him.
Setlik III would again be mentioned when O'Brien was arrested on false charges, but for all of the damage that it has done to the Irishman's life, it has never once been officially depicted.