Mari Perkins as a baby was given to an orphanage. She recently was told that somebody had actually come looking for her but was sent away, so she decides she has to go to London to see if she can find them. She desperately needs to know who her family is. She leaves the country and moves to London to take on a governess job arranged by an agency. After having her belongings stolen Mari arrives late to the agency and is told that the job is no longer available. The owner of the agency also refuses to look for any other work for her. It is fortunate then that as Mari is leaving the agency she overhears another governess saying that she had quit her job as governess for uncontrollable twins of a Duke. Mari decides there and then that she must take this chance.

Edgar Rochester is the Duke of Banksford and he only recently found out that he is the father of nine-year-old twins, a girl and a boy. Their mother is dead and the children now reside with him, but they are so unruly that he can't keep a governess. When Mari (rhymes with starry) turns up, she is so genteel and young that he can't believe that she will be able to take the children in hand. She manages to convince him to give her a week-long trial.

With her understanding of insecurity in life, she easily sees that the children are playing up because they feel insecure. They are also homesick for France, and they miss their nursemaid. They are also unsure of their father who they still call 'sir' because he always seems angry at them. He is always working either at his foundry or working on the model of his steam engine that he is trying to bring into production.

Mari is on a mission, she wants to bring happiness to the children. She wants their father to have a loving relationship with them, and she also needs to find out who she is. Unfortunately, she also finds herself having feelings for Edgar, and he in turn with her, but they can have no future. They are separated by class differences and her lie by omission about not actually being sent from the agency. Is there any hope for them? What of Mari, will she achieve her goals?

WHAT A DIFFERENCE A DUKE MAKES is a beautiful story that captured me from the very first pages. I loved how I was made to feel the gamut of emotions from happiness and joy where I would laugh out loud, to tearful moments when I would need a tissue. Of course, the romance of the story was a delight to read and I found myself sighing often. Edgar came across as not so nice when the story began, but as he grew emotionally he became the perfect hero for the story. I loved watching how he progressed all thanks to his sweet governess. His sister, India, is a fabulous character. I enjoyed her part in the story, too, and I am very much looking forward to reading her story next. I fully enjoyed WHAT A DIFFERENCE A DUKE MAKES and definitely recommend it.