If you like a good puzzle, mystery, or loved The Da Vinci Code, you’ll probably enjoy this book. Ottavia Salina is a nun who enjoys a celebrated career working in the Vatican Archives. Her life is a simple and quiet one, until one day she is asked to help decode symbols tattooed on the body of a dead Ethiopian. No one will tell her who he is or what he’s done, only that she needs to figure out what the markings on his body mean. It is to be her main priority, and a Swiss Guard Captain, Kaspar Glauser-Rvist will be assisting her.

The mystery and unanswered questions are too much for her, and on a visit home, she has a nephew assist her with searching the internet, in the hopes of finding information on her dead man, which she does. Almost more than she wanted to know. She then confronts the captain with her knew knowledge, and finds herself dismissed from her job, and exiled to Ireland. Disheartened, she arrives in Ireland only to find important men waiting to take her to a plane to send her back to Rome.

After this dizzying turn of events, she finds that the Captain had gone to bat for her, insisted she be a part of his time, receieve an apology, and get her job back, before he would go forward with the project set to him by the Vatican. At long last, Dr. Salina gets her answers. Their dead ethiopian stole a piece of the True Cross. It was not the only theft of its kind. The Vatican wants to get to the bottom of these thefts, and to find the people responsible for them. This is the task set to Dr. Salina, the Captain, and eventually, their partner Farag Boswell.

Using Dante Alighieri‘s Divine Comedy as their guide, the three puzzle their way through a series of tests set forth for aspirants wishing to gain membership in the oldest religious order in existence: the Staurfilakes, protectors of the True Cross. Their lives, needless to say, will be changed forever.