Transporter and holosuite malfunctions trap Sisko, Kira, Dax and Worf in Bashir's '60s secret-agent fantasy.
Garak finds his loyalties torn when Enabran Tain, his former mentor, orders him to interrogate Odo; the Tal Shiar and Obsidian Order join forces to attack the Dominion.
Deep Space Nine is granted a new tactical asset, the powerful warship Defiant; to avert invasion, Sisko searches Gamma Quadrant for the Founders, the unseen leaders of the Dominion.
The Dominion tricks Sisko into a confrontation with the Tzenkethi that could lead to full-scale warfare.
Tensions escalate when it appears the Federation has handed over DS9 and the entire Bajoran sector to the Dominion.