Please note this is not a stand alone novel, but is number 4 in the series.

The Holy Father sends Martinelli into Rome to negotiate with the Mafia in regard to an old wooden box, filled with ancient documents and Nazi letterheads, where he is confronted by an evil priest from his past.
Front page news in Switzerland, has Martinelli sent on a special mission by the pontiff, where he meets up with an old friend, Enrico, and the hunt begins for a most important religious relic. An unusual adversary stands in his way, but Martinellis appetite for killing vampires is once again satisfied.
Enrico, Wilhelm and Martinelli return to Bavaria, and a solution to a previous puzzle is finally concluded.
Martinelli returns to the Vatican City; he visits the Holy Father to enquire about the letterheads, and finds himself imprisoned below the Basilica. Will Martinelli cope with the many dark secrets that the Vatican has hidden over the centuries, and will he be able to keep his faith in the church?
But what about Sofia Graeco? Will she eventually become part of his life? Or will Martinelli keep her at a distance?