The Scandalous Widow by Bree Verity

Young widow Lady Juliet Hampshire jumps at the chance to be involved in an espionage mission into France – she will do anything to avoid having to think about her dwindling finances and the necessity of catching a wealthy husband. It is just a shame that her traveling companion is to be the stuffy, snobby Lord Alistair Chisholm. But there is more to the wounded Lord Chisholm than Juliet can see.

Alistair has been chasing redemption for years, ever since he accidentally killed his older brother in a drunken brawl. Now the heir to his father’s Marquessate, he should be staying at home, finding a wife and siring children, but he can’t rest until he atones for his grievous sin. And as an experienced spy, he can’t understand why the untried, scandalous Lady Hampshire is involved in his mission.
Thrown together and required to work closely, they quickly realize their first impressions of each other are mistaken, and passion flares between them, with both of them assuring the other the liaison will cease when they return to London.

But when first one and then the other falls in love, can they overcome injury, familiar strangers, capture and the deepest of betrayal in order to claim their happily ever after?