Stardate 49962.4: Klingon Chancellor Gowron has sent a communiqué to the Federation demanding that they stay out of Klingon territory or risk starting a war. While being set up on a date by Garak, Odo begins to succumb to a sickness that will eventually destabilize his entire body, rendering him unable to change from a liquid to a solid.
When the Cardassian occupation of Bajor ended in 2369, the mining space station Terok Nor was left abandoned, its systems ripped out. By invitation of the Bajoran provisional government, Starfleet stepped in to oversee the rebuilding and day-to-day operations of the newly christened Deep Space Nine.
The years of Starfleet's nonintervention into Cardassian matters, however, had taken its toll on relations with the Bajorans. Consequently, Starfleet's position was a tenuous one; many Bajorans, suspicious and hostile as a result of decades of Cardassian oppression and brutality, did not greet the Federation's presence with open arms. The Federation's assistance is put to the test as DS9 becomes a center of travel and commerce that stretches into the Gamma Quadrant.