Mystery fiction. Detective and mystery stories. 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. The fact that the Vatican is neutral territory in German-occupied Rome is only one of the obstacles Billy must overcome. First is a harrowing journey, smuggled into Rome while avoiding the Gestapo and Allied bombs....

Returning to 1944 Italy to tackle two cases, including the murder of an accountant who may or may not have had military connections, U.S. Army Lieutenant Billy Boyle begins to suspect that his superiors do not want him to solve the murder.

A German-sponsored IRA uprising is suspected when fifty Browning Automatic Rifles are stolen; Billy Boyle is sent to recover the weapons, but bodies accumulate as Billy finds unexpected challenges to his Boston-Irish upbringing and IRA sympathies.

"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....

"Months after the Liberation of France, ex-Boston cop Billy Boyle has landed in its war-torn capital city, still carrying with him the weight of his last mission. He witnesses a Paris ailing from the carnage it has endured-blocked roadways, buildings marked by bullet holes--but with the nascent hope that the war might be coming to its end. When Billy and his long-time comrade Kaz survive a tense shoot-out in the Père Lachaise Cemetery, they discover...

Billy Boyle is sent to London to investigate the murder of a Soviet embassy official, which may be a revenge killing in response to the execution of twenty thousand Polish officers by the Soviet secret police.

"A murder in wartime Switzerland reveals Swiss complicity with the Nazis and profiteering during World War II Billy and Kaz are sent to neutral Switzerland to investigate the murder of a Swiss banking official with ties to the Office of Strategic Services (OSS). The US and Swiss governments are about to embark on diplomatic discussions regarding the Safehaven Protocols, which are aimed at limiting the amount of war materials exported by Switzerland...

"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,...