Star Trek: Deep Space Nine/Recap/S01/E01 E02 Emissary

Following a 60 year occupation, the Cardassia Empire has withdrawn from Bajor, leaving behind a planet stripped of many of its natural resources and a population scarred by decades of subjugation and mistreatment. The Federation has agreed to help the planet rebuild, and to this end, it will be sharing command of the abandonded Cardassian space station Terok Nor (now renamed Deep Space Nine) with the Bajorans. Commander Benjamin Sisko will be in charge, but he still has issues from the loss of his wife at the Battle Of Wolf 359, and to make matter worse, he also has to deal with his Bajoran first officer, who is deeply mistrustful of Starfleet and even her own government and the damage done to the station as the Cardassians left.

Taking a short trip around the Bajoran system in a Runabout, Sisko and his old friend and science officer Dax discover a stable wormhole to the Gamma Quadrant, but on the return journey, Sisko is captured by the aliens who live inside the Wormhole, who dump Dax back on DS9. While Sisko tries to explain the nature of linear time and corporeal existence to the Sufficiently Advanced Aliens, the crew on the station must race to move it to protect the wormhole from the Cardassians, who are on their way back with a renewed interest in Bajor...

Tropes

 * Contemplate Our Navels: The whole long sequence where Sisko explains the circumstances of existing in linear time to the Prophets boils down to this.
 * Establishing Character Moment: Sisko essentially blackmailing Quark into staying on the station really sets him up as the most pragmatic of all the Star Trek captains.
 * First Episode Spoiler: Averted - The station is in orbit around Bajor at the beginning; its move to the wormhole entrance is reflected in the opening credits of every episode except this one.
 * Humanity On Trial: Not just humanity, but all corporeal beings. Sisko makes the case, and is thus deemed the Emissary.
 * Mind Screw: The Prophets sequence looks like one... until you understand the argument and why it is presented as a conversation superimposed on events of Sisko's life; it's how the Prophets are able to communicate with and relate to this alien human.
 * Patrick Stewart Speech: The baseball scene with the Prophets.
 * White Void Room: With an closeup on Sisko's head... then his face... then his eyes... then just one eye.