Song of the huntress / Lucy Holland.

Britain, 60 AD. Hoping to save her lover, land and her people from the Romans, Herla makes a desperate pact with the king of the Otherworld. But years pass unheeded in his realm, and she escapes to find everyone she loved long dead. Cursed to wield his blade, she becomes Lord of the Hunt. And for centuries, she rides, reaping wanderers souls. Until the night she meets a woman on a bloody battlefield a Saxon queen with ice-blue eyes. Queen Æthelburg of Wessex is a proven fighter. But when she leads her forces to disaster in battle, her husbands court turns against her. Yet King Ine needs Æthel more than ever: the dead kings of Wessex are waking, and his own brother seeks to usurp him. Ines only hope is to master the magic that's lain dormant in his bloodline since ancient days. When their paths cross, Herla knows its no coincidence. Something dark and dangerous is at work in the Wessex court. The Otherworld seeks to rise, to bring the people of Britain under its dominion. As she and Æthel grow closer, Herla must find her humanity - and a way to break the curse - before it's too late.