4-01: The Way of the Warrior, Part I
When a Gowron-lead fleet of Klingon attack ships arrives at DS9, Sisko calls in a familiar Klingon expert for reinforcement.
A survivor found aboard an ancient Bajoran ship claims to be the true Emissary of the Prophets.
4-25: Broken Link
When Odo is struck with an unknown illness, Sisko seeks help from The Founders, who enact a punishment against Odo for harming another Changeling.
4-09: Our Man Bashir
A transporter mishap converts several crewmembers into spy-themed holosuite characters, with their true memories erased and their lives linked directly to the program.