Commander Sisko returns from Starfleet Command with a new warship prototype, the U.S.S. Defiant NX-74205. Sisko brings with him Romulan Subcommander T'Rul to oversee the Romulan cloaking device and Lt. Cmdr. Eddington as Starfleet Security Chief. Hoping to avert an invasion, Sisko takes his officers into the Gamma Quadrant to find the mysterious founders of The Dominion.

Avery Brooks (Cmdr. Benjamin Sisko)
Rene Auberjonois (Odo)
Siddig El Fadil (Dr. Julian Bashir)
Terry Farrell (Lt. Jadzia Dax)
Cirroc Lofton (Jake Sisko)
Colm Meaney (Chief Miles O'Brien)
Armin Shimerman (Quark)
Nana Visitor (Major Kira Nerys)

Martha Hackett (Subcommander T'Rul)
Kenneth Marshall (Lt. Cmdr. Michael Eddington)
Salome Jens (Founder)
John Fleck (Ornithar)

• This is the first appearance of the Founders, and Salome Jens as their leader.
  
• The DS9 crew begins using the new Starfleet insignia communicator badges designed for Star Trek: Generations and Star Trek: Voyager in this episode.
  
• Sisko was on the design team for the U.S.S. Defiant NX-74205 while stationed at Utopia Planitia. The Defiant was designed to battle the Borg. However, design flaws during the shakedown cruise caused Starfleet to abandon the project.
  
• The Defiant is outfitted with a Romulan D'Deridex-class warbird cloaking device. The Romulan government loaned it to Starfleet for use only in the Gamma Quadrant in exchange for intelligence information on the Dominion.
  
• Lt. Cmdr. Eddington is assigned as the station's new Starfleet Chief of Security, much to Odo's displeasure.
  
• Ornithar, a Karemma official, is brought aboard the Defiant and reveals to Quark and Sisko that a race called the Vorta has ordered all communications for the Dominion directed to a relay station on Callinon VII. The Ferengi negotiated the tulaberry wine contract with the Karemma in the 2nd season episode "Rules of Acquisition".
  
• Martha Hackett (T'Rul) will go on to portray Seska on Star Trek: Voyager.
  
• Dax has a new (bad) hairdo in this episode.