Dax and O'Brien have found a cache of Cardassian files - Kira's somewhat pissed off at the file on her. Meanwhile Kai Opaka, some religious figure from Bajor, turns up on the station so she can be all mystical and obscure in space as well. Since it's a slow work day, they volunteer to take her on a trip through the wormhole. On the way to the Runabout, she presents O'Brien with a gift for his daughter - a TARDIS key.
When they reach the other side of the wormhole, the Kai gets to be mystical and obscure on the other side of the galaxy. Then they receive a message, which she suggests they investigate. They find a planet with satellites, one of which shoots at them and disables the ship. The runabout crashes, and the Kai karks it, then people turn up with gun.
On DS9, they're starting to send out the search parties.
Sisko and co have been captured by the Ennis who at war with another race called Nol-Ennis, as the leader Golin Shel-la explains. Kira angsts about her dead Kai some more. Then some Nol-Ennis turn up and there's a firefight, with Kira taking out three of them. While they're picking through the bodies of the Ennis, Kai Opaka stumbles into the cave, apparently resurrected from the dead.
While Bashir gives her a good scanning, the Ennis start rising from the dead too. They've landed in an X Men comic? Bashir says there's biomechanical stuff inside her fiddling with her biology. Shel-la explains this sort of thing happens a lot. It's a punishment for their ongoing war. Kira scoffs at the Ennis' war-making abilities, and Shel-la says it's because they don't care any more. Sisko offers to transport everyone off the moon if they'll arrange a cease-fire.
Meanwhile, Dax and O'Brien turn up with their brains to work out how to find and rescue Sisko and his pals. Dax calls O'Brien on a piece of technobabble he just pulled out of his arse, and he admits he just made it up, but he'll build something anyway.
Kira angsts at the Kai. Whine, whine, whine, sheesh. Then the Kai gives her a Vulcan nerve pinch to shut her up, but apparently they don't work on Bajorans, because Kira just starts crying.
O'Brien's technobabble invention locates the downed runabout and they set course.
Ennis and the Nol-Ennis talk cease-fire, and Sisko gets pissy when Bashir suggests this might go against the Prime Directive. Unfortunately the cease-fire talks break down and another fight starts. Bashir tells Sisko that he's discovered that they can't afford to die on the moon. Once someone's been resurrected, the bionanites are permanently attached to their system, and they can't leave the moon.
The satellites are no match for Dax and O'Brien's brains, and they communicate with Sisko on the moon. Bashir thinks he can reprogram the bionanites to let the people on the moon die, but Shel-la's reaction to the news does not go down well, and they opt to just leave. The Kai, of course, stays on the moon, presumably to try to get some peace going. Teh end.