There were a couple of hundred men at Trinity, but they were so spread out over hundreds of acres that only a few could be seen at a time. Still, the closer the convoy got to Ground Zero, the more evidence of activity there was: a cable strung on a seemingly infinite line of stakes; the first blast-wave gauge, a box designed to bounce in the springs of a hoop; photographic bunkers gray as shells on a beach, their periscope stalks aimed south at a tower seven miles off in the clear, trembling air. Six miles from the tower, the convoy reached the North-10,000-meter shelter, a timber bunker that sank into a protective slope of raw earth. Bulldozers browsed on the slope, tamping it. From North-10,000, a fresh blacktop road ran straight to the shot tower. Single cables multiplied into racks of wires. Planted in dead sage was an unmanned instrument bunker, a concrete block with portholes for cameras.

“Skyshine hole.” Jaworski pointed to the single socket aimed away from the tower. “To monitor the general neutron scatter.”

Skyshine? It sounded pretty, like a glitter of sequins shot in the air.

“Nervous?” Joe asked.

“Things have changed,” Jaworski said. “We used to detonate shells using a long string. No one had a gauge. A charge worked or it didn’t. No oscillographs or ionization chambers. What hasn’t changed is that there will only be a handful of men who actually assemble the bomb. There’ll be a hundred others screaming that this seismograph is vital or that pressure gauge must be repaired, but the only thing that counts is the weapon, right? Of course, in the war against the Kaiser we dropped nothing much larger than grenades from planes, and there was definitely no background neutron scatter.”

The tower called Ground Zero looked like an oil rig without the pipes, a spindly structure of steel beams and tie braces that rose a hundred feet to a galvanized-iron shed perched in the sky. One tower leg had a ladder to landings every twenty feet all the way to the top. A wooden ladder reached from the bottom landing to the ground, where Foote was waiting in his sombrero and British Army shorts. His high-explosives team of a half-dozen draftees sat in undershirts, bathing shorts and handkerchiefs worn on the head pirate style. As the convoy wound around and stopped at the tower base, CID officers jumped from the two security sedans and formed a skirmish line, pointing submachine guns at cactus and rabbit brush.

Foote ambled at their backs. “ ‘They seek him here, they seek him there, those Frenchies seek him everywhere. Is he in Heaven, is he in Hell, that demned elusive Pimpernel?’ Joe, you brought my goods?”