Feared as a demon because of his two different colored eyes, as well as by his outlandish actions, Highlander Onyx MacKeefe is known as a madman. While celebrating his birthday one cold night at a Lowland pub, he meets a bonnie Englishwoman who says she is searching for her father's murderer and thief. And when he recognizes the name of the person she seeks as his own mother, his birthday takes a bad turn.

Lady Loveday de Lacy, known as Lovelle, comes looking for not only a murderer from the past, but also something that's been stolen - her mother's Book of Hours. She is desperate to find it, as she needs the help of the mystical charms at the back of the book. But when she meets a rugged Highlander who takes her captive in order to secure his mother's life, she finds herself being reckless, and also attracted to the dangerous man.

But things only become more complicated as Lovelle and Onyx find themselves needing each other, but knowing they are enemies. And the more they try to fight off the attraction between them, the stronger it becomes. But neither of them see the harrowing future in store for them as Onyx is faced with demons of his past and there is also an outbreak of the plague that threatens their very lives.

Can a proper Englishwoman and a Scottish madman find the strength and will to work together before impending doom overtakes them?