What happens when angels must die? Eric Thorn has learned more than he ever wanted to know about this question. When Amalia first asked him the question in Cappadocia he laughed it off thinking it was late night conversation for a dig site of religious significance. But years later, after the Grigori have taken Amalia from him, he knows that there are angels that must die. He knows that it is his work to answer the question. A chance encounter with long-lost friends provides a new wrinkle as Eric seeks to eliminate the remaining Grigori - the last of the 200 Watchers placed on Earth. Now he must also seek the missing daughter of the young woman who saved his sanity 20 years before. To complicate matters, the Daughters of Samael appear to be working with at least one of the Grigori. Since when did the Fallen side with the Watchers?