LieutenantBilly Boyle could have used a rest after his last case, but when hisgirlfriend, Diana Seaton, a British spy, goes missing in the Vatican, where shewas working undercover, he insists on being assigned to a murder investigationthere so he can try to help her.An American monsignor is found murdered at thefoot of Death's Door, one of the five entrances to Saint Peter's Basilica. WildBill Donovan, head of the OSS, wants the killing investigated. The fact thatthe Vatican is neutral territory in German-occupied Rome is only one of theobstacles Billy must overcome. First is a harrowing journey, smuggled into Romewhile avoiding the Gestapo and Allied bombs. Then, to learn the truth about themurdered monsignor, he must navigate Vatican politics and personalities—someare pro-Allied, others pro-Nazi, and the rest steadfastly neutral. But that'snot his only concern. Just a short walk from the Vatican border is the infamousRegina Coeli prison, where Diana is being held. Can he dare a rescue, or will afailed attempt alert the Germans to his mission and risk an open violation ofVatican neutrality?