The explosive final instalment in the Ferrishyn trilogy.

The conflict between USUK and the Fenodyree has finally come to an end, but Lucile is gone and war against the Fomorians is looming in both Eamhain and Mag Mell.

With her sanity hanging by a thread, Lucile has to decide whether to accept her destiny as the Great Serpent's champion or embrace the dark power of the Morrígan.

Meanwhile, Jacob must figure out how to save the woman he loves, at the same time as defending Tír na nÓg and High King Manannán from a seemingly unstoppable force of Fomoire warriors.

Vox is faced with protecting the human city of New London from Fomorian invasion, as well as finally coming to terms with his true feelings for Lucile, and Niamh and Dea have to decide where their loyalties lie.

As new alliances are formed and old allegiances are tested on the battlefield, will love or hate prevail?