Hide & Seek chronicles the intensely personal war between wartime Rome’s Nazi SS Chief Herbert Kappler and the Vatican’s Monsignor Hugh O’Flaherty, a fiercely fought rivalry that culminated in Kappler attempting to kidnap and murder his Irish opponent, who was determined to fight Rome’s Nazi rulers. Called “Ireland’s Oscar Schindler,” O’Flaherty masterminded a large-scale operation from inside the neutral Vatican, to hide and help Jews, downed airmen, and escaped Allied prisoners. Using safe houses and church buildings, the priest sheltered around five hundred Jews in the Holy See and many thousands more Jews and Allied escapees in and around Rome.

After a Resistance bomb killed thirty-two German soldiers, an enraged Hitler ordered revenge. Kappler planned and oversaw the firing squad execution of 335 people in the Ardeatine Caves outside Rome. The massacre became the worst atrocity committed on Italian soil during the war. After the war, the Nazi colonel was found guilty on all the charges relating to the massacre and sentenced to life. Amazingly, O’Flaherty began visiting his former rival in prison, engaging in a long-run conversation that led to Kappler’s conversion—and baptism by the Irish Monsignor.