Exhausted by the demands of her healing gift and eager for adventure, Peregrine Alcott bargains her way on an expedition to the mythical Island she's been obsessed with since childhood, where hidden relics and long-forgotten history await.

On the journey, Perrin finds friendship in a cartographer similarly keen to uncover the Island's secrets, a team that offer a reprieve from her overwhelmed magical senses and an unexpected reunion with an acquaintance from her past: Sloane Montrose, a calm and composed swordfighter whose presence unsettles Perrin more than the Island itself.

Following her own instincts - and curiosity - Perrin heads into ancient ruins, where she discovers cavernous tunnels, unusual animals and a darkness determined to cast a shadow over their camp. As the legends of the Island stir, Perrin finds what she never thought to seek: love that will last a lifetime.