When I think about love and mysteries, I think about all the stories where you have a basic story line of Boy meets Girl, then a brief fluttering of hearts before somebody that both Boy & Girl know is murdered, each behaves suspiciously for one reason or another (either for reasons totally unrelated or because they're each trying to cover up something they think is a sure pointer that the other did it and they don't want to believe it and they certainly don't want the the police/detective to know about it), then the real murderer is caught, and Boy and Girl tumble joyfully into one another's arms with the implication that they will live happily ever after. A variation on this theme is that, usually, the Boy is the detective and he knows that despite the Girl acting suspicious she can't possibly be guilty because he's fallen for her (within, like, minutes) and he's got to prove her innocent. The official police naturally make things difficult for the Girl, but she is ultimately proven innocent (often due to the Boy's efforts) and, again, Boy and Girl tumble joyfully into one another's arms with the implication that they will live happily every after.
Dorothy L. Sayers set out to make this scenario a little more realistic. She's been criticized by some for dragging out the romantic wranglings of Lord Peter and Harriet Vane over three books--and those who do not care for Miss Vane are most vocal about all she put poor Lord Peter through. But, honestly, after having just been put through the hell of being innocent and yet barely escaping the gallows by the skin of her teeth (the skin of Miss Climpson's most determined teeth, that is), I can't blame Harriet for feeling bruised and just wanting to get away from everything that reminds her of the ordeal--including, the knight-in-shining armor who helped proved her innocence. And I find it refreshing to have an intelligent heroine who questions whether a relationship built on gratitude would really last (no matter how much she might be attracted to Peter). It doesn't seem to occur to most mystery heroines (and their author/creators) that relationships built in the intense emotion of a murder investigation might not last once the emotion dies down.
Harriet's reactions to Peter's persistence seems to me to be exactly right for an intelligent woman who quite likely also spends a great deal of time thinking about emotions and motivations and the consequences of actions--after all, she's a mystery writer and is used to examining what makes her characters tick--at least enough to provide motives for murder and enough emotional energy to throw around some red herrings. I imagine Harriet is, like me, prone to overthinking--and she's concerned that she would be rushing into a relationship as a safe harbor after the storms of standing trial for her life. She wants time to work out who she is now that she's been accused and finally set free from prison. She certainly won't make a suitable companion until she's more steady on her feet.
I think what I appreciate most about the Wimsey-Vane love story is how much Peter grows during the three books. He starts out quite selfish, really. He finds what he believes to be the one and only woman and he blurts it all out to her...right there in prison where she has very little options before her. He's quite sure that once she's seen enough of him, she'll believe he's the one and only man as well. But...by the time Gaudy Night rolls around, he's learned enough about her and about love that having saved her life (and in a way owning it), he gives her life back to her. He gives her the means to protect herself from the deranged mind behind the poison pen notes, but acknowledges that it's her right to put herself in danger in the course of the investigation. He trusts her as an equal and once she sees that, she also sees how far she's come from the events in Strong Poison. She's more sure of and comfortable with herself. And is finally ready to recognize the true feelings--beyond what was overwhelming gratitude--that she has for Peter.
