Stardates: 46379.1 - 46393.1
The setting is "deep space" where the inhabitants of the planet Bajor have recently driven out the occupying forces of the Cardassians, who for many years systematically stripped Bajor of its natural resources. Bajor, impoverished and ravaged is now on the brink of civil war. The United Federation of Planets has been invited by the provisional governement to take over a space station orbiting Bajor, Terok Nor, abandoned by the retreating Cardassians. The station, renamed Deep Space Nine, has been trashed by the departing Cardassians.
Commander Benjamin Sisko is sent by the Federation to take command of the station and make it functional while helping Bajor work towards membership of the Federation. . Sisko is accompanied by his young son, Jake. Jake's mother had been killed three years previously when the Borg, led by the assimilated Jean-Luc Picard, attacked a starship defending a federation outpost.
Sisko's team on the station includes a Bajoran first officer, and veteran resistance fighter from the Cardassian occupation, Major Kira Nerys, a science officer, Jadzia Dax who is a Trill (a species where two entities are joined in a symbiotic relationship), a shapeshifting security officer, Odo, who has served in that role for the Cardassians, a chief of operations, Miles O'Brien, recently transferred from the USS Enterprise and a newly-qualified chief medical officer, Dr Julian Bashir.
Shortly after Sisko takes up post, he discovers a wormhole in space near the station. A wormhole is a shortcut in space. This one allows spacecraft to travel 70,000 light years to a distant part of the galaxy, in the Gamma Quadrant, in moments - instead of the usual 65+ years....
The discovery of the wormhole has been long foretold on Bajor. They regard it as the celestial home of their deities, the Prophets and the spirtual leader of Bajor considers Sisko to the messneger or "emissary" of the Prophets whose coming has long been predicted in Bajoran folklore and religious life.
Travelling through the wormhole, Sisko encounters the beings who live there. The wormhole aliens live in non-linear time. They cannot conceive of a universe or species which expereiences past, present and future as separate states. They initailly wish no contact with such an inferior species. Sisko manages to show the aliens the challenge of living with a future which is unknown, and convince them of the qualities of faith, courage and hope this requires and nurtures in species which live in time. Impressed, the aliens agree to allow passage of vessels through the wormhole.
Sisko's encounter with non-linear time makes him realise his life and emotions have been stuck at the point of his wife's death. He accepts he has to move on from his intense and unyielding grief and try to make a new life for himslef and his son on Deep Space Nine.