Broken Engagements and Other Adventures

She's been left behind by her childhood sweetheart.
He's been jilted by his fiancée.
Her sweetheart left her for his fiancée...

Miss Rosemary Griffiths has been looking forward to the day her childhood sweetheart returns from his year abroad. He promised to make their secret engagement public, and her life will finally start moving forward.
But he returns, and there is no engagement. There is only the discovery that Frank has 'outgrown' her. He has decided he wants a woman of passion, and Rose is too calm and practical. That, and he is to inherit both a title and an estate from a distant relative and has found a wife with money.
Rose is left with broken dreams, a shattered heart, and a list of things they were going to do once they married.
So, she sets out to 'undo' all the things on that list by doing them backwards. Or in the opposite direction. Whichever. She is determined to prove that she can be contrary when she puts her mind to it.
But this is 1870s England. Going anywhere as a young unmarried woman requires that she go with her doting, but overwhelming, family in tow.
Then, while contriving to take the stage to the resort that was supposed to be her honeymoon destination, she meets Mr. Walker. When the two of them keep bumping into each other at the resort, it comes to light that they are there under similar circumstances.
It only takes a short conversation for Rose to figure out their situations aren't just similar; they have a detail named Frank in common: Mr. Walker's former fiancée is going to marry the new Duke of Windham.
The two wind up in several hilarious escapades as they try to help each other finish the things on their lists to spite the people who hurt them, while also trying not to get themselves into a romantic entanglement with each other.
But when Mr. Walker's list is finished, will that put an end to their burgeoning friendship? Or have they stumbled upon something neither thought possible?