"Lieutenant Billy Boyle could have used a rest after his last case, but when his girlfriend, Diana Seaton, a British spy, goes missing in the Vatican, where she was working undercover, he insists on being assigned to a murder investigation there so he can try to help her. An American monsignor is found murdered at the foot of Death's Door, one of the five entrances to Saint Peter's Basilica. Wild Bill Donovan, head of the OSS, wants the killing investigated....

In his time investigating crimes for both the Boston cops and General Ike's European forces, Lieutenant Billy Boyle hasn't encountered a serial killer. But now it looks like he may--a serial killer with a particularly frightening agenda

"It's September 1944, and the US is poised to launch Operation Frantic, a shuttle bombing mission to be conducted by American aircraft based in Great Britain, southern Italy, and three Soviet airfields in the Ukraine. Tensions are already high between the American and Russian allies when two intelligence agents--one Soviet, one American--are found dead at Poltava, one of the Ukrainian bases. Billy is brought in to investigate, and this time he's paired,...

"1943: In the midst of the brutal, hard-fought Solomon Islands campaign between the Allies and the Japanese forces, Lieutenant Billy Boyle receives an odd assignment: he's sent by the powerful Kennedy family to investigate a murder in which PT skipper (and future president) Jack Kennedy has been implicated. The victim is a native coastwatcher, an allied intelligence operative, whom Kennedy discovered on the island of Tulagi with his head bashed in....