4-21: For The Cause
Sisko's loyalties are tested when his girlfriend, Kassidy Yates, is an accused Maquis collaborator.
4-07: Little Green Men
Quark, Rom, and Nog accidentally transport themselves back to the Roswell Incident on Earth in 1947.
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.
4-19: Shattered Mirror
The mirror Jennifer Sisko lures Jake and Benjamin to the alternate universe to assist with building another U.S.S. Defiant.