This is a story related achievement which will unlock with natural story progression.
Shortly after you have returned the kitten to it's owner and found Big Danny, you will need to talk to Bella in the brothel again. Once you complete your conversation with her she will give you a box of perfume.
Your next task will be to find a book in the local bookstore near Baker St. As you enter the store you will need to talk to the clerk, he will mention he knows about the book but needs help sorting the ordering.
Once you add all the cards in the correct place the clerk will tell you where to find the book. The achievement will unlock once you collect the book from the shelf.