An explosion at a Federation/Romulan diplomatic conference reveals that Changelings have infiltrated Earth. Sisko and Odo are dispatched from Deep Space Nine to Earth in hopes of preventing a Dominion takeover. While there, Sisko is placed in command of Starfleet Security on Earth. With his son Jake, Sisko takes the opportunity to visit his father, Joseph, in New Orleans. However, it's not long before the seriousness of the Dominion threat becomes apparent. Rumors develop that certain members of Starfleet have been replaced by Changeling counterparts. When Earth appears to have become defenseless, Sisko declares a State of Emergency and prepares for war with the Dominion.

Brock Peters (Joseph Sisko)
Robert Foxworth (Admiral Leyton)
Herschel Sparber (Federation President Jaresh-Inyo)
Susan Gibney (Commander Erika Benteen)
Aron Eisenberg (Cadet Nog)
Dylan Chalfy (Head Officer)

• This story is continued in the next episode, "Paradise Lost".
  
• The wormhole has been repeatedly opening and closing, with no ships coming through. The crew suspects a cloaked Dominion fleet.
  
• Susan Gibney also played Dr. Leah Brahms in the Next Generation episodes "Booby Trap" and "Galaxy's Child".
  
• Brock Peters, who plays Ben Sisko's father, also played Admiral Cartwright in Star Trek IV: The Voyage Home and Star Trek VI: The Undiscovered Country.