Physiologist Ainslie Grey believes that love is merely a combination of chemical reactions and bodily processes. However, his sister's fiance reveals a past marriage to a woman who, unbeknownst to him, is now married to Grey.

Enjoying a break in Wales, Philip Hardacre meets the mysterious and beautiful Julia Lambert. But when he tries to relocate to a secluded house near the Cader, Julia become fearful and tries to persuade him otherwise...