Checkmate, My Lord by Tracey Devlyn

A desperate mother falls in love with the spymaster she's sent to betray.

Spymaster Sebastian Danvers, Lord Somerton, has spent the last decade protecting England's shores against a French invasion. Known for his cold logic and ability to sacrifice anything for the greater good, few can outwit him, and even fewer dare challenge him. Until now.

After being exiled to his country estate, Sebastian is surprised when his beautiful, no-nonsense neighbor turns her seductive wiles on him. But years of intrigue have left him wondering why a respectable widow would risk scandal for a few nights in his bed. Sebastian takes his time unraveling the widow's secrets, for he quickly realizes she might be the one sacrifice he is unwilling to make.

Living a quiet existence at Winter's Hollow, Catherine Ashcroft spends her days doing little more than caring for her precocious six-year-old daughter and negotiating her neighbors' various complaints against their absentee landowner, the enigmatic Earl of Somerton. But, all her boredom comes to a searing halt after learning her newly returned neighbor might have had something to do with her husband's murder.

Catherine's orderly existence soon upends and she now finds herself in a desperate bid to save her daughter's life. But she must betray the earl to do so, even though she no longer suspects him of foul play. Lauren succumbs to the the earl's passionate kisses and recognizes the same loneliness she has felt for years lurking in his hard, crystalline eyes. As her lover's enemies close in, will Catherine be able to save both her beloved daughter and the handsome spy who has stolen her heart?

This book is part of the "Nexus" series.
Here are some other books from this series: