Evil for Evil (Billy Boyle World War II Mystery)

Fifty BARs (Browning automatic rifles) have been stolen from a U.S. army base in Northern Ireland. His uncle Ike Eisenhower sends Billy to recover the weapons, which might be used in a German-sponsored IRA uprising. Bodies begin to accumulate as Billy finds unexpected challenges to his Boston-Irish upbringing and IRA sympathies. There are rogues on both sides, he learns.