Star Trek: Deep Space Nine (sometimes abbreviated to DS9) is a science fiction television series set in the Star Trek universe in the Milky Way galaxy, in the years 2369–2375. In the beginning of the season 3, Sisko takes the new USS Defiant into the Gamma Quadrant to find the mysterious leaders of the Dominion and avert a war. Meanwhile, Odo is drawn by instinct towards his home planet in the Omarion Nebula.