Private Rome by James Patterson

A priest is murdered and a Private agent is the number one suspect. Jack Morgan is in Rome celebrating the opening of a new local Private office, when the party takes a deadly turn. Private agent Matteo Ricci is found at the party standing over the body of a dead priest with a gun in hand, swearing he did not kill the man. As Jack tries to prove Matteo’s innocence, he uncovers a much deadlier conspiracy – which leads him straight to the heart of the Vatican. With corruption closing in on all sides, Jack must decide who he can trust before the city falls.