TNG Season 2 Episode 20 "Emissary" is about a Klingon ship from Kirk era waking up from cryo sleep in the 24th century. Dukat's first appearance is DS9 Episode 1, also called Emissary, even though Marc Alaimo did play a different Cardassian in TNG
My God though, Kai Winn is effing evil. Louise Fletcher plays her so well. Very Nurse Ratched.
