"Emissary" is the premiere episode of Star Trek: Deep Space Nine.
Lieutenant Commander Benjamin Sisko is first officer aboard the USS Saratoga while it battles the Borg led by Locutus, the former Captain Jean Luc Picard, at Wolf 359. When the ship takes a direct hit, which kills most of the bridge crew and causes the start of a warp core breach, Sisko helps civilians get to the escape pods. In the crew quarters he finds his son, Jake, buried under a pile of rubble, but Sisko manages to free him. Sisko also tries to save his wife Jennifer, but she has already been crushed to death by the falling debris. Despite this, Sisko still tries to free her body in vain, and is ultimately dragged away by a crew member to an escape pod. Together with Jake and other survivors, Benjamin flees the doomed Saratoga moments before the ship explodes.
Stardate 46379.1: Three Years Later
Commander Benjamin Sisko approaches Jake, now a teenager, who is fishing in a lake. Jake asks his father questions about the Cardassian space station they're going to and why they can't just live on Bajor, the planet the station orbits. Commander Sisko assures Jake that he will have fun and meet lots of new friends, but they are interrupted by a voice from the bridge, informing Sisko that they are approaching Deep Space 9...