When Rosie Treloar discovers her fiancT is an unscrupulous conman, she flees London for her native Cornwall. Here, she takes a job as a tourist guide and meets American Ben Goodman, who is researching the mystery of his family's legacy, lost during the English Civil War. Rosie, increasingly attracted to Ben, becomes involved with his mission, unaware that there are other sinister forces seeking the legacy - forces which could threaten her newfound happiness with Ben.