Two On A Tower - Thomas Hardy
I have to agree with many other reviewers: this was not one of Hardy's best. One of Hardy's favorite themes was exploring the social roles of women. While he succeeded in Tess of the D'Urbervilles and Far From the Madding Crowd, I feel he quite missed the mark in Two on a Tower,

It is the story of Viviette and Swithin. I continuously vacillated between being annoyed with Viviette and sympathizing with her. She seemed to be in love, but her extreme caution made her come across as indecisive. The little experience she had with men had taught her to be cautious: her husband was a brute and she did not want to end up a victim again. And poor Swithin, so clueless about love and women, just allowed himself to be led.

Hardy also made ample use of another device seen in his other novels: the near miss. There were so many times where they were moments away from living happily ever after, but fate always intervened. And in the end, the greatest obstacle seemed to be that Viviette was SOOOO much older than Swithin: a whopping 8 years. Note extreme sarcasm :P Swithin himself was taken aback by the change in her when they finally reunited at the end. At 33, she was middle-aged and haggard. How times have changed! A woman of 33 today is just as appealing to a man of 25 as a woman his own age.

I think I would have forgiven most of these things, or at least looked less unfavorably on them if it hadn't been for the ending. I found it to be too abrupt and implausible.