“Past Prologue” is episode three of season one of Star Trek: Deep Space Nine.
Following the events of the two part opener, “Emissary”, Deep Space Nine has been moved to a position near to the wormhole that leads to the Gamma Quadrant. The discovery of the wormhole makes Bajor a much more important place.
A Bajoran ship being pursued by a Cardassian warship comes into the system. The ship is destroyed, but the pilot, Tahna Los, is successfully beamed onto DS9 first. He’s a former associate of Major Kira’s, and he’s part of a Bajoran group that has performed acts of violence against the Cardassians – who want him as a terrorist – and against Bajorans they disagree with. The man says that he has now given up violence.
Two Klingon women, Lursa and B’Etor, arrive on the station shortly afterwards. They are outlaws, and they have caused problems in TNG before. Doctor Bashir makes the acquaintance of the sole Cardassian left on the station, Garak, who professes to be a simple tailor but who everyone thinks is a Cardassian spy.
The three events are all related. Tahna may have given up violence, but he hasn’t given up his aims, which are a little short-sighted. He, like Kira, isn’t that happy to have the Federation around – there’s a feeling that they’ve swapped one set of masters for another – but Kira believes the Federation to be a necessary evil whilst Bajor rebuilds.