“Emissary: Part 1” is the first part of the feature length – or two part – first episode of season one of Star Trek: Deep Space Nine.
The episode opens back during the Borg battle at Wolf 359 in The Next Generation episode, “The Best of Both Worlds”. Commander Benjamin Sisko is serving on board one of the destroyed ships, and his wife is killed in the battle, although he and his son survive.
Three years later and he is assigned to command Deep Space Nine. This is a former Cardassian station orbiting Bajor. The Cardassians have left, leaving both the planet and the station rather the worse for wear. Sisko himself doesn’t want to do the job either, and is planning to quit Starfleet and return to Earth. His second in command, the Bajoran Major Kira, isn’t happy about the Federation’s presence either, and has a rather pessimistic outlook on what is going to happen.
This episode crosses over with The Next Generation episode, “Birthright: Part 1”. There’s a guest appearance by Jean Luc Picard, and Sisko most definitely bears the Captain a grudge – Picard, as Locutus of Borg, was in charge of the Borg cube at Wolf 359, and Sisko blames him for his wife’s death.
The Bajoran religious leader – the only person with a hope of holding the planet together – views Sisko as a saviour, and shows him their most prized treasure, an Orb. The story continues in “Emissary: Part 2”.