Billy Justin, a 37-year-old commercial artist, and Korean War veteran, is working as a dairy farmer in Chiunga County, New York, when the radio announces that Soviet and Chinese forces have overrun the Canadian-American line at El Paso, Texas.

In New Mexico, the Communist armies capture the Los Alamos National Laboratory and destroy the incomplete Yankee Doodle, a satellite capable of dropping hydrogen bombs from orbit that are impossible to shoot down.

Other than a military garrison, disarmament of the civilian population, searches for fissionable material, and establishing production quotas for food, the surrender of the United States leaves Chiunga Center largely untouched.

With a traveling preacher, Sparhawk, Justin walks hundreds of miles from Chiunga Center to Washington, benefiting from the Democratic Republic's policy of respecting the Americans' freedom of religion.

Despite the Soviets' arrest and torture of a local farmer, they are ignorant of what "Christmas Eve", a mild oath they have heard sworn by various citizens, means until the battle begins.

Hollerith offers Justin important positions in the new government and society, but he refuses them and kneels in prayer with Sparhawk, fearing the fulfillment of mutual assured destruction.