"Emissary" is the two-part opener, comprising the pilot and second episodes, of the science fiction television series Star Trek: Deep Space Nine.

A new crew takes command of a distant space station and makes an astonishing discovery that will change the galaxy.

Commander Benjamin Sisko is assigned by Starfleet as station commander of "Deep Space Nine" in orbit of Bajor, previously used by the Cardassian Union during its occupation of the planet, now repurposed to help Bajor to enter into the Federation. Sisko is resentful of the duty, having lost his wife Jennifer three years previously during the Borg attack at Wolf 359 and destruction of his former ship, the USS Saratoga, and worried about the well-being of his teenage son Jake while on the station. When he and Jake arrive, they find the station nearly stripped bare of unessential systems by the Cardassians, and the Bajoran staff, led by Major Kira Nerys, distrustful of Starfleet's presence. As the USS Enterprise delivers more Starfleet staff, including Chief Miles O'Brien and his family, Sisko becomes more despondent at the prospect of living on the station as he gets his final orders from Captain Picard, the man Sisko holds responsible for Jennifer's death. Sisko informs Picard that he is contemplating resigning from Starfleet to seek a civilian position, but continues as ordered to perform his job as station commander.

With the help of Odo, a shapeshifter who is the station's chief of security, Sisko manages to convince the Ferengi barkeeper, Quark, to remain aboard the station, helping to keep the station as an active waypoint for ships as well as providing Jake a friend in Quark's nephew, Nog. He later visits the spiritual leader Kai Opaka on Bajor, who shows him the Orb of Prophecy and Change, one of several similar orbs believed to be sent by the Bajoran Prophets. Sisko looks into the Orb and finds himself reliving the moments when he met Jennifer for the first time. After his vision, the Kai tells Sisko that she believes him to be the "Emissary", a messiah figure who will help Bajor, and gives him the Orb to study further. When Sisko returns to the station, he finds the rest of his staff has arrived, including Chief of Medicine Dr. Julian Bashir and Science Officer Lt. Jadzia Dax, whom Sisko happily recognizes as a Trill and the current host of his former friend Curzon Dax. Sisko gives Dax the Orb to study for a scientific explanation of the way it works.

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