Maxine Kordell's high school reunion is marred when al-Qaeda hijacks her plane, a female gang accosts her, her friend Marty Blair is murdered, and she's threatened by a drug cartel, coyotes, and the police. Joined by Mena Harling and Willi Mayers, 3-M investigate, but are almost killed while in custody. Haley joins them, but events intrude involving lost Francisco Goya paintings, a Jim Bowie silver hoard, Sherlock Holmes, Pope Pius XII, The Cluster, a list compiled by former Vice President Aldrich Fellerson implicating The Vatican in war crimes, and a plan for hiding the list devised by Holmes. So Pope John Paul II brings the foursome to Rome, where they're caught in a feud between two cardinals and become targets of the Mafia. 3-M and Haley soon learn their foes include four professional assassins. Aided by born again Christian/Sherlockian Nora Kelly, they find a letter from Holmes, pursue the treasures and list, then Max must face Marty's killer, whose lethality may exceed her own.