After receiving a minor dose of radiation poisoning, Chief O'Brien inexplicably begins experiencing a series of jumps into the future. Meanwhile, a Romulan delegation arrives on DS9 expecting an intelligence report on the Dominion in exchange for the continued use of the cloaking device aboard the Defiant.

Smiley O'Brien from the mirror universe kidnaps Commander Sisko and convines him to impersonate his deceased, mirror universe self in order to persuade the alternate version of his dead wife, Jennifer Sisko, to join the Terran Rebels.