A brief explanation of this condition courtesy of Wikipedia: The Fregoli delusion, or the delusion of doubles, is a rare disorder in which a person holds a delusional belief that different people are in fact a single person who changes appearance or is in disguise. The syndrome may be related to a brain lesion and is often of a paranoid nature, with the delusional person believing themselves persecuted by the person they believe is in disguise.
So having this element in the story just added to it. While I thought the romance was fine between Harper and Aiden, it was predictable. Also, I did not like that Harper right away fell for Aiden. I mean, she barely new him and she was kissing him. Otherwise, I really liked this book.