Unbeknownst to Kira, Dukat has a secret agenda when he offers to assist rescue survivors of The Ravinok.
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.
4-06: Starship Down
Upon rescuing an alien ship, The Defiant is badly crippled by the Jem'Hadar and becomes trapped in a gas atmosphere.