The Mormon Temple swung to the north and shrank to the size of a claim stake under the immense Utah afternoon. The mountains started huge and grew. As the convoy gathered speed through the wide Jordan Valley, Ray looked as if he were entering a black tunnel.

The square and straps were designed to protect the suspended canister from shocks, but it didn’t protect the drivers from the sight of the canister. It trembled in midair when the ambulance rolled over a cattle guard; it swayed as the road turned. For all its sleekness, the canister had a pregnant quality. The slug deep inside it seemed, in Joe’s mind, alive. It was an interesting concept: metal that was alive. Not simply a mineral capable of some sort of chemical reaction, but so alive with alpha activity that the water around the slug was warmed to a hundred degrees.

“Magnificent, the sun and these Wasatch Mountains.” Santa twisted this way and that for better views. “You boys must love this run.”

“ ‘Machine Gun Joe was a rough and ready redskin,’ ” Joe sang softly, “ ‘He’ll never let plutonium touch the ground. / And he always will remember the Seventh of December, / With his be-bop-a-rebop and he’ll blow-em down.’ I’ll tell you what we’d be doing if we weren’t doing this run,” Joe said to Ray. “We’d be somewhere in the South Pacific digging mass graves in a coral reef. We’d be burying pieces of bodies that were six months old, with one dull shovel for the two of us.”

“The South Pacific, you think?” Santa asked.

“Somewhere where no one would find us until the war was one year over,” Joe told Ray. “We’d be playing poker for seashells.”

The whites of Ray’s eyes were turning from pink to acid red.

“Why us?” he demanded.

Santa fell atypically silent. The convoy gained altitude at the Mormon hamlets of Orem, Provo and Helper, touched down the Colorado River at Moab and then rose again up the La Sal Mountains. Ray’s blood went on pooling in his eyes. He pointed out every dead rabbit carcass on the road with his tommy gun and laughed uproariously.

The amphetamines made Ray worse, but not much worse than in the first run he and Joe had made, when he had sobbed the whole way. He was a primitive Sicilian, and he thought radiation—any radiation—caused cancer. With his poker winnings he could afford to pay other enlisted men to pull his hazardous duties. He was never within a hundred yards of radioactive material except when he and Joe were ordered to run the slug.