Okay, you really should read the first two books in this series to gather the understanding of where this tale begins. Although, each book, a recap of previous events occurs when the story requires it.
She is home in Denver, after fleeing Italy, after a shocker of a day. He is in Italy, trying to do his daily grind, wondering what went on, to have the girl he had feelings for, having fled without an explanation, but on the same flight as her ex-fiancee.
Complicated, it's just getting interesting!