Returning from a conference, Chief O'Brien and Constable Odo are paid a visit by a Changeling. However, the Changeling calls himself a Metamorph. He, like Odo, was one of the one hundred shape-shifters sent out by the Founders at an early age in order to experience other species' ways of life. The Metamorph has been trying to return home ever since. Luckily, Odo is the first shape-shifter that the Changeling encountered.
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.