The Emissary: Worf's ex comes to visit.
Worf appears to be doing well at poker. Why is Data dealing Pulaski in to the next hand if she's run out of chips? The game's interrupted by a "class eleven Star Fleet alert" diverting them to a set of co-ordinates. After some speculation, Admiral Grommit (sorry, "Gromek") contacts them to tell them that an envoy is going to rendezvous at the contact point - the envoy being on a class 8 probe.
After a ridiculously tense interception, they transport the probe on board, and out pops K'Ehleyr, a half-human/half-Klingon (fortunately she got her teeth from the human side). Worf is somewhat cranky - they seem to have a History together. That or it's just Worf's time of month.
K'Ehleyr explains there's a Klingon ship named the T'Ong on the way back with a crew who've been in cryogenic sleep since the Federation/Klingon war. When they wake up, they'll think the war's still on. Picard assigns Worf to help her work out what to do, much to his distress. K'Ehleyr bonds with Troi over being half human and then goes to chat with Worf, who's no less hostile than before. The discussion soon becomes heated and she storms out, returns to her quarters and starts breaking things. Troi pops in to suggest the holodeck might be less breakable.
Worf, meanwhile, is on the bridge and grumpier than ever. Picard tells him to relax. "I AM RELAXED." He proceeds to the holodeck to find K'Ehleyr in combat with his calisthenics program. After she rubbishes his program, he tells the computer to start level 2. After more combat, hand-porn ensues, and off-screen mating. Then she makes him talk about his feelings and he demands she marry her, at which she pisses off. Worf isn't a big believer in casual sex.
In case you've forgotten the B-plot, there's a scene on the bridge where they're still looking for the Klingon ship.
Worf brings Data in on his meetings with K'Ehleyr. Data seems to be the go-to guy for that sort of thing, huh? but it doesn't stop K'Ehleyr trying to make Worf talk about his feelings some more. The command crew have a discussion about what they're going to do about the T'Ong, at which point Data reports they've detected a ship. It turns out to be the T'Ong, which fires on the Enterprise and then cloaks.
K'Ehleyr says they should attack, and let the Klingons die like Klingons, but Worf has another solution. Worf poses as the captain of the Enterprise, claiming that the Klingons won the war. Fortunately the bluff works, and they turn over command of the T'Ong to K'Ehleyr. In the transporter room, she snaps at Worf and makes him talk about his feelings again. Leave the poor boy alone! There's more hand-porn (Klingon style) and then he beams her over to the Klingon ship.