Star Trek story involving the "Battle of Wolf 359"
Visual reference of Rene Auberjonois' character helping the doctor to compress a man's wound in order to save blood.
Picard makes a crossover appearance wishing Sisko luck, while O'Brien transfers to DS9 from the Enterprise.
We see a glimpse of what happened at Wolf 359 - a battle that happened during "Best of Both Worlds, Part 2"
Miles O'Brien tells about Seltik III. In "The Wounded" the fact he is a hero of Seltik III was introduced, including details of the events Miles is refering to.
Kai Opaka mentions that Sisko once offered her a tour on DS9. He did so in "Emissary"
There is another visit to the Prophets of the Wormhole, with similar effects, but this time played for laughs.