I've read several Heyers, many of which are some of my all-time favorite books, but even so I had some misguivings about reading "The Reluctant Widow" since reading the comments here and finding out that it was more focused on mystery than on romance. I decided to read it anyway, not wanting to pass on anything written by Heyer, and I am happy to say I was greatly surprised by how much I enjoyed this book!
I loved both the story and the characters, and found myself constantly chuckling over the bizarre situations poor Elinor finds herself every day. The suspense in this book never ceases to keep the reader interested, the humor is always present (keep an eye out for Nicky and his dog, it nearly always kept me in stitches), and the relationship between Carlyon and Elinor is always engaging to read, despite their many differences and her obvious (and understandable) initial dislike of him. The resolution to the mystery was also unexpected... the villian was somebody that certainly commanded my respect, evil and merciless at he was, he was a great character.
I also have to say that I disagree with the reviewer who said there was no romance here. It is subtle, but it is always there, I at least had no difficulty in deciphering the reasons behind Carlyon's interest in Elinor's welfare, however intent he was in hiding his sentiments from her. I think he might have fallen in love with her at first sight too, though perhaps he wasn't aware of that until much later... in any case, I greatly enjoyed his bantering with Elinor, perhaps the only female who didn't treat him with the respect and almost reverence he was accustomed to. His declaration of love certainly was no surprise to me, and it was very satisfying.
All in all, a definite keeper!