The Royle sisters arrive in London determined to uncover the mystery surrounding their birth. It is their belief that they are the triplets of Mrs. Fitzherbert, the mistress of the Prince. Mary gets sidetracked from their mission when she falls in love with Viscount Wetherly. With single-minded determination, Mary sets out to bewitch the viscount. Unfortunately, Mary discovers the viscount's brother, Rogan, is equally resolved that she not marry into the family. As Rogan places obstacles in her path, Mary accepts the challenges and tries to outwit him.

After watching his stepmother manipulate his father, Rogan, the Duke of Blackstone, distrusts women in general. He believes marriage is a business arrangement between families and does not intend to let his little brother fall into a trap with a wily woman. After meeting Mary, Rogan begins his campaign of ploys and distractions. Finding himself in a game with a worthy opponent, Rogan discovers he is attracted to the tenacious vixen.

As the campaign of wills mounts, Rogan and Mary realize their perceptions of each other are undergoing a dramatic change. Anger and resentment are giving way to affection... and possibly love?

The first in a trilogy, HOW TO SEDUCE A DUKE, successfully interlaces the Royle sisters' mysterious background with an entertaining romance and a strong conflict between the protagonists. Ms. Caskie gives readers a pleasant tale that warms the heart.