Driven from her home, Naela, the Sareen, flees across the Limpic Ocean to Fontaine, where she comes upon an horrific experiment to uncover the secret of the Sareens' immortality.
At the same time Tethys is finally rediscovered. Agents of the Authority land in Fontaine, determined to make their way to the Valley, in order to eradicate the 'Restorer' infestation they have detected there. Soon they and Naela cross paths; with unexpected and fateful results for them all and this world alike.
Fontaine is the fourth novel about the world called 'Tethys'. The tale began with Keaen, Finister and Tergan. The battle for the survival of the people of Tethys continues in Tethys.