The investigation into Harkup's death continues and Book discovers something surprising about the bomb site skeletons. The killer is brought to book.

In post-war London, Gabriel Book, a literary enthusiast and bookseller, combines his day job with his favorite hobby — helping solve knotty murder cases. Although happily married to his best friend, Trottie, Book is a gay man at a time when homosexuality was illegal. When a new assistant, Jack, arrives at the bookshop, it soon becomes clear his appointment wasn’t as random as it at first seems.