Caleb is book 4 in the series and gives us some backstory on Caleb's life before he became a bodyguard for Billie, the 4 years of being her bodyguard in Paris, and then snippets of his POV when they moved to New York. 

For everyone who has read the first 3 books, we know how deeply Caleb cares for Billie and his job of protecting her. I loved how we were able to get more of his POV and the happenings behind the scenes that we did not get from Billie's POVs in the previous books. I'm looking at you, Mr. Ambassador! How dare you?

And I was not prepared once again for the ending 🥺, I honestly thought I was since I knew what was going to happen but the waterworks were in full force.