Isilia Greigrove looks exactly like her twin sister Isolda… only, in truth, she is a changeling fairyfolk of the Good Court left in the cradle of a human infant. Sili always knew she was not like the others. Her own unpredictable magic forced her to run away with Isolda from their hometown, wiping away all memories of herself. And because of an ill-fated robbery, the sisters had to set out to find a treasure whose secret reaches deep into human and fairy history. Very soon, Isilia and Isolda will understand that fairy secrets are worth far more than gold. But can a changeling rein in her power to protect her sister—and herself?