In 2373, a Pah-wraith inhabiting Chief O'Brien's wife Keiko forced Miles to perform a series of modifications to Deep Space 9's deflector grid, transforming the station into a massive chroniton array aimed directly at the Bajoran wormhole, where the temporal disruption would kill all of the Prophets. O'Brien was able to successfully complete the modifications, but instead of aiming the chroniton beam at the wormhole, he targeted the runabout which he and Keiko were aboard, driving the Pah-wraith out of Keiko's body. A year later, when a Prophet and a Pah-Wraith inhabited the bodies of Major Kira Nerys and Jake Sisko, respectively, the crew developed a plan whereby a chroniton generator could be utilized to drive the entities out of their bodies, by ramping up the chroniton levels slowly, g