Rapture: Bajor's acceptance into the Federation is immanent, but Sisko is having visions.
Sisko, Kira and Dax are looking at an ancient matt painting of a lost city, being returned by the Cardassians. There's a obelisk in the picture which has the coordinates to the city, but because only one side is visible... Sisko looks at a scan of the painting and finds there's a reflection of the other side of the pillar. He's able to reproduce the pillar in a holosuite. Quark interrupts him to snark, and when Sisko goes to save the program, he's knocked on his arse by an exploding console.
Odo takes arresting Quark as a first step. Bashir checks Sisko out and says he's all right. Jake cooks dinner. Apparently Kasidy Yates is coming to visit the next day. Sisko plays with his food. Later, as he's studying the pillar some more, he's contacted by Star Fleet to hear that Bajor's admission to the Federation is going to be approved.
The station prepares for the ceremony, with Quark being particularly excited. Kira is optimistic, and finds Sisko in the holosuite with his pillar, in some sort of trance. She manages to rouse him, and he claims he was in the lost city of B'hala. He says he had a vision of the past and future, which Kira says was a sacred vision. O'Brien contacts them to say that Kai Winn is on her way. Oh, crap. Unsurprisingly, Sisko wants to stay in his holosuite program.
Kira meets Kai Winn at the airlock and trades barbs. Kasidy finds Sisko in the holosuite and he invites her with him on a trip to Bajor to find B'hala. After a ride in a runabout, they wander around in in a cave. Eventually they reach a wall, which Sisko phasers through to reveal... the pillar from the painting. That was quick.
Worf and Odo argue over accommodations for the visiting Star Fleet officers. Kira is preoccupied by Sisko's discovery of the lost city. Kai Winn drops by for a word with Kira about Sisko - the discovery has convinced her that Sisko truly is the Emissary. Kira says it's brave of her to admit she's wrong, and gets a lecture about how Winn was locked up in a prison camp during the occupation.
Admiral Whatley finds Sisko at the B'hala dig, concerned that Sisko is spending more time on the dig than on the admittance into the Federation. Sisko wants to hang out at the dig in search of enlightenment. Whatley says to report back to the station for a physical the next morning. The next morning, Whatley talks to Bashir about Sisko's visions. Eventually Sisko turns up in a swarm of Bajorans, dispensing wisdom before he suffers some sort of attack and tells Whatley that his son forgives him.
Bashir starts hooking Sisko up to machines. Sisko's still having visions, of a cloud of locusts heading for Cardassia. Bashir says his ganglia are depolarising or something. He wants to repolarise them, but it'll mean the visions will stop. The alternative is that Sisko is likely to die. He refuses the operation. Jake and Kasidy try to reason with him, but he's attached to his visions. Kai Winn pays them a visit to let Sisko know it's time for her to help him in his quest.
The senior staff debate whether Sisko's making the right decision but seem evenly split. Sisko, meanwhile, is taking a trip with the Orb of Prophecy. Whatley is getting impatient that Sisko is't around for the signing, and starts the ceremony without him. Sisko staggers in and rambles about locusts, announcing that Bajor must not join the Federation before collapsing.
Sisko is whisked to the infirmary, but Kira says that Sisko didn't want the operation. Bashir says he can't proceed without Jake's permission. Jake tearfully apologises to his father and gives permission. Kai Winn is unimpressed that Bashir is operating, and says the Bajorans have decided to delay entry into the Federation.
Sisko wakes up distraught that the visions are gone. Whatley later visits him to ask him to try to persuade the Bajorans to change their minds, but he's certain he was right. Sisko is sure that Bajor will join someday. He goes back to his quarters for a family moment with Jake and Kasidy.