In a house, in the rain, an old man injects himself with something. A young woman rings the doorbell, and he lets her in. She's a writer, who's looking for the old man - Jake Sisko, her favorite author. They have tea, and she asks why he stopped writing. Jake says it started when his dad died. After a brief interruption by the title sequence, Jake continues that his dad invited him on a trip to the Gamma quadrant while he was writing a short story. FLASHBACK!
As they were hovering by the wormhole in the Defiant, there was some turbulance and the warp core began to breach. Sisko and Jake nipped down to the engine room to deal with it - Sisko shut down the core, but was zapped by energy from the warp core and disappeared. There was a memorial service, of course.
Flashfoward to Jake, who was still upset at losing his father, and uncertain what to do. After turning in, he had a vision of Sisko appearing briefly in his quarters. More months passed, Bajor entered into a pact with the Cardassians which made the station a likely target for the Klingons. Sisko appeared again in a corridor - this time he stayed there, and was able to be taken to the infirmary. The theory was he'd been pulled into subspace and was unstuck in time. Despite putting up a containment field, Sisko disappeared again.
Authorgirl says the story is taking a toll on Jake and she should come back another time, but oldJake admits that won't be possible, as he's dying. After the ad break, he admits that he's just mentioning about the inevitable and not literally dying that moment. *facepalm* oldJake continues that Dax and O'Brien continued working on the problem until Star Fleet was forced to turn the station over to the Klingons, and Jake had to leave. He went to Earth and settled in Louisiana where he became an author and married. FLASHBACK!
Jake and his wife Korena invited Nog to dinner. Nog reported that he had visited the station and Morn was still there, running the bar (Rom and Quark having left). Later that night, Sisko appeared in his living room. Sisko was happy to meet Jake's wife and see the books he'd written and dropped hints that he'd like some grandchildren. After Sisko's subsequent disappearance, Jake began studying subspace mechanics. Fifty years after the original accident, they headed back to the wormhole ready for the impending inversion.
Trying to replicate the accident, Jake was pulled into subspace with Sisko. Sisko was upset that Jake gave up his marriage and writing to chase after him. Jake reappeared back on the Defiant as Sisko was trying to make him promise to stop and live his life.
OldJake tells his friend that he's realised that if he dies while his father's materialised in the present, it'll fix the problem. After some final advice, she leaves, and Jake continues to wait.
Sisko finds Jake sleeping and wakes him - Jake explains what he's done, much to Sisko's distress. Back in the past, Sisko jumps out of the way of the discharge from the warp core, and the Defiant flies on through space.
What a beautiful and touching episode.