Genre: historical romance, already married.
Spoiler free description: I think my favorite romance gimmick is marriage of convenience, but a close second is the already (unhappily) married. This book starts with unhappily married Nathan and Evie having lived apart for 3 years. Though it's not clear on the back cover blurb, the death of their infant son caused the breakdown in their marriage, which just wasn't strong enough to survive their grief. However, a scandal brewing in London has Nathan bringing Evie home, whether she likes it or not. How they work through things from there is a great story, though more of a tear jerker than I normally like to read.
The best:A very good look at the grieving process and what can tear people apart and what can bring them together. Not rushed, good pacing.
The worst: Actually, a little too much history for me, though that would probably be a strong point for someone else.