In Purgatory's Shadow (I)

When the station picks up a mysterious coded message from inside the Gamma Quadrant that appears to be Cardassian, Garak is asked to analyze it. He reports that the message is insignificant, but is later caught trying to sneak off the station in a Runabout. He admits that the message is some sort of distress call from his mentor Enabran Tain, the former head of the Obsidian Order. Garak convinces Sisko to allow him to travel to the Gamma Quadrant to search for Tain, but Sisko sends Worf along as a chaperone.