Farther on, they found more physicists digging up the cables they had buried the day before, because they had buried the cables taut and, under the weight of the earth they’d thrown back on, the cables had snapped. Two other physicists stood mournfully at a silver barrage balloon. The helium balloon was designed to carry neutron counters aloft, but Trinity’s elevation was so high and the air so thin that the balloon clung to the desert floor. On a gentle rise stippled with piñons a radiologist had strung wires on the branches and was hanging white mice from the wires by their tails in order to determine the effect of the blast on living organisms. The first mice had already perished from the heat.

“He’s been out in the sun too long himself,” Joe said after Oppy had sent man and mice back to the Base Camp.

“It all looks so sane on paper. Do you have a drink, Joe?”

“Sorry.”

“Since when don’t you have a flask? You’re looking fit all of a sudden, unlike me. Two days ago I touched the plutonium. I told Harvey it was shaking. He said I was shaking.” Oppy took a deep breath. “So, Mescal-eros?”

“Just what Groves was afraid of, I guess. They still think this is Stallion Gate. They still chase horses out of the mountains and round them up here.”

“I recall the mustangs we saw.”

“The trackers come in around dusk and stay until dawn. They’re bound to see the shot unless I cut them off.”

“That means you wouldn’t be getting back until morning. You may miss Trinity entirely.”

“You don’t want any roast Apaches, do you?”

At the West-10,000 bunker, Oppy left the jeep to talk to meteorologists releasing weather balloons. The balloons bounced as they rose, as if they were rolling up an invisible hill.

Behind the bunker, Ray Stingo was riding on a Sherman tank taking a practice spin, treads flattening cactus. The tank had been painted white. The cannon was removed and the machine guns were replaced with automobile headlights. Air bottles for the crew were clamped to the side armor. Behind the turret was a rack of rockets.

Ray jumped from the tank. “Isn’t it amazing, Chief? Lead-lined, air-filtered, air-conditioned. This baby’s the first thing in after the blast to collect samples. The way they do it, they’re going to ride up to the crater and shoot rockets with scoops on one end and cables on the other. They just pull the rockets back. Now that’s a garbage truck!”

“Sounds like the garbage truck of the future.”

Joe studied the seam of black above the mountains. It was the clouds from last night. Patient clouds.