Bound in Bone & Briar. The Bloodroot Oaths, #2

He killed her husband. Now she owns his life. Maeve Rowan has spent a year watching the man who made her a widow slowly die. Under the ancient laws of the grove, Lorcan Blackmere owes her a blood-debt-his life force draining day by day, grey creeping into his hair, strength fading from his massive frame. She should feel satisfied. Instead, she feels nothing at all. So she summons him. Not to forgive-but to understand why his suffering doesn't feel like justice.
Lorcan arrives expecting death. What he gets is servitude: one year and one day in Maeve's household, after which she'll decide his fate. He accepts without hesitation. A year of service is better than he deserves. But Maeve's crumbling estate needs more than a servant-it needs a protector, a partner, someone present in ways her glory-seeking husband never was. As the seasons turn, Maeve discovers that the grief she's been carrying isn't simple-she's mourning a marriage she never truly had.
And Lorcan, the man she blamed for her pain, is the first person who's ever seen her clearly. When old secrets surface and enemies close in, Maeve must decide: release the debt and let him go, or claim something far more terrifying than revenge. In the grove where all debts are paid, love might just be the most dangerous currency of all.