Over a hundred years after she went missing, Isolde, born to the family of a famous Irish king and a powerful immortal, inexplicably reappears.

Her mother's kin, the Descendants, are one of the two magical races of Ireland. But no Descendant can understand the reasons for Isolde's disappearance, and worse yet, she is giftless - born with no magical ability, a dangerous thing when the magic-rich Fomorians, ancient enemies of the Descendants, are growing in strength.

The Fomorians no longer control any Irish kingdoms, but they still desire control over the mortal world.

They seek to spread their dangerous webs wider by manipulating England's Norman lords to invade Ireland.

Not yet eighteen, Isolde's world is about to change for ever. But when death and destruction seem inevitable, her true worth will show itself, for Isolde is far more than she seems.