Fountain of Secrets by Josic Litton (2003, Paperback)

In 1837, Akoran aristocrat Gavin Hawkforte travels to the deserted island of Deimatros where a traitor tried to murder his parents. He is surprised to be greeted by a woman called Persephone who claims she lives on the island now. She is curious as to why he has come to Deimatros and he tells her he is conducting a century old survey on some geological points. Persephone explains to Gavin that an ancient volcano that once destroyed much of the Akoran archipelago is awakening. As Gavin and Persephone work together to try to stop the volcano from erupting they find themselves falling in love. However, Persephone has a secret about her family that makes it impossible for anything to happen between them once Gavin learns the truth.

Josie Litton keeps this series fresh with a twist that brings it full circle for her fans.