Spy Glass (The Glass Series Book 3)

the long version

After siphoning her own blood to defeat her enemy, Opal Cowan lost everything—including her powers. Moreover, her choice has made her immune to the effects of magic. Once a trusted protegee, Opal is now an outsider looking in, spying on those with the powers she once had, powers that make a difference in her world. Until spying through glass unlocks something new within her. Suddenly the beautiful pieces she makes flash in the presence of magic. She also discovers that someone has stolen some of her blood for nefarious purposes—and that finding it might allow her to regain her powers. As she sets out on a new journey, she’ll learn, once and for all, if her powers are lost forever… and what she would sacrifice to regain them.