“For the Cause” is episode twenty-two of season four of Star Trek: Deep Space Nine.
Captain Sisko has got rather close to Kasidy Yates, so it’s a bit unfortunate when Odo and Commander Eddington approach him with circumstantial evidence that she is trading with the Maquis. At the same time, a shipment of replicators is being sent by the Federation to the Cardassians to help them get back on their feet. When the Defiant follows Kassidy’s ship into the Badlands, they see it meeting with a Maquis ship, and transporting something across. Sisko will face some hard choices, and there are twists he can’t see coming.
Back on DS9, Garak starts interacting with Gul Dukat’s daughter, Ziyal, who after the events of “Return to Grace” is now living on the station with Major Kira. Dukat doesn’t like Garak, and Kira doesn’t trust him, so there’s plenty of opportunity for things to go wrong. However, Garak and Ziyal are the only Cardassians on the station.