"Something Borrowed, Someone Blue" is the twenty-third and final episode in season 7 of American sitcom Frasier. It is an hour-long episode, and is notable because it brings to a climax the romantic character arc between Niles and Daphne, a significant running plotline for the first seven years of the show's production.
When Martin gives Daphne the bottle of wine as a wedding gift, Daphne break downs once more. Frasier is left to comfort Daphne, and Daphne reveals that she knows about Niles' seven-year crush on her. She has tormented herself about her own feelings towards Niles, and believes that she has fallen in love with him in return. Despite her impending marriage, Frasier urges her to confront Niles and discuss this with him before her marriage. When Niles returns, however, he has exciting news: he has, on impulse, eloped with Mel and married her.
That night following the rehearsal dinner, Frasier and Martin discuss Daphne and Niles. Frasier confesses that he does not believe either Daphne or Niles when they claim to be happy, leading Martin to warn him about interfering; two marriages are at stake. Meanwhile, Niles and Daphne join each other for a dance, and Frasier watches them as they dance close together. Cornering Niles in a hotel room, Frasier reveals that Daphne knows how he feels towards her, and that there is a possibility she shares his feelings. Niles is tormented, but resolves to talk to Daphne to find out. Managing to get Daphne alone, Niles confesses that Frasier has told him of her feelings towards him, and tells her that he loves her. Before they can discuss anything, they are constantly interrupted, firstly by Martin, then by Donny, then Mel, and finally by Daphne's entire family. Escaping the party to the balcony, the two stand together awkwardly, until Daphne takes action, and the two share their first kiss. She then tells him that they have made too many commitments to others to back out now. Niles is left on the balcony, alone.
The next morning, as the wedding taking place, Niles sits in the front cabin of the Winnebago, unable to watch Daphne be married. Martin and Frasier join him, Frasier bringing with him the rare bottle of wine to honour Niles' bravery in at last opening his heart to Daphne. The three men prepare to enjoy a glass, only to discover that the wine is undrinkable; unfortunately, Morrie kept his wine rack in the boiler room. Frasier and Martin leave to attend the wedding, leaving Niles alone, until a knock at the door rouses him. He turns to see Daphne, before him in full wedding dress, asking him if he wants to go on a date. She has chosen him after all, and as the two prepare to flee the wedding, Daphne realises that she can finally call him "Niles".
Niles has just given Martin the news that he and Mel are now married. Martin is stunned, and unsure how to react Martin: So, you're happy, right? Niles: Happy? I'm delirious! Martin: Yeah, you'd have to be, wouldn't you?
The final words of the episode, as Daphne and Niles prepare to leave the wedding together in the Winnebago Niles: Fasten your seat belt, Daphne. Daphne: Fasten yours, Niles!