Silver in the Bone - Alexandra Bracken

To obtain a famous ring and break the curse, embark on a fatal hunt driven by love, revenge, and pure adrenaline.

Tamsin Lark has always been a treasure hunter and Hollower. She goes on her most deadly expedition to date when there are rumors of a strong ring from Arthurian mythology that will lift her brother's curse.

However, Tamsin was forced to form an alliance with her adversary Emrys, the last person she can trust, because she is not the only Hollower who desires the ring. From below Boston, they must travel together to the haunted remains of Avalon, where the spirits of the past wait...