Surprise! Counselor Troi has a fiancée (Wyatt) and he's come to marry her. Troi thought that her old vows had faded into oblivion, but both sets of parents are set on the arranged marriage. The Enterprise agrees to host the wedding and Troi goes along with it because she says Riker isn't willing to put her above being a star ship captain some day. Riker pouts because it's true. Wyatt and Troi are getting along well despite their parents' squabbles, when suddenly an ancient ship of plagued humanoids shows up. Wyatt recognizes a woman on board as the woman of his dreams (literally) and the wedding is called off when he beams himself about, exposing himself to the plague.
I have to say that this is my favorite episode so far*, excluding the two-parter opening, which can't fairly be compared because it's twice as long. This episode was awesome because of the character interaction. We get to see Riker pout and Data make fun of drunk people ("Please, continue the petty bickering!").
Normally I would think I'd hate an episode that was all about Troi, but the writers show once again that they know how to delve into a character. Troi shows marvellous poise when dealing with her little-known fiance, then reasonably throws a fit when her mother is causing a scene. She deftly ignores Riker's pouting, telling him straight out why she's not cancelling the wedding for him, and giving him a fair chance to object. Since she's a Betazoid, she also doesn't freak out about dream-woman. It's also nice to see how utterly annoying her character would be if she were like her mother, an eccentric woman who expects others to suck it up when she offends them. It really makes you feel like all her stupid lines previously aren't the character's fault, like the character is a distinct entity who is unfortunately sometimes over-taken by terrible writers.
The ending was a bit touching, but not over done. Troi's a little emotional because she was getting along with her future husband pretty well, but it's like she doesn't forget that she essentially just met him.
I mean, there's always Riker, right? Noooooo!
*even though Wil Wheaton isn't in this episode