Martin Smith - Stallion Gate

The truck drove directly under the wide callipers of a chain and pulley that was suspended down the centre of the tower. When the truck's tarpaulin was removed, Joe and Ray bolted the callipers to the bomb. Steel cable groaned as it turned through the pulley sheave. The truck rolled out from under and the dangling bomb was lowered to a knee-high steel cradle, where it resembled a globe on a stand, a matt-gray moon four and a half feet wide, with two rims and patches where the detonator ports were taped. As soon as Ray disengaged the callipers and the pulley was lifted free, Foote's men set a canvas tent over the bomb and the security cars drove off.

"Want to join the pool?" Foote asked Joe. "A dollar apiece."

"For what?"

"The bang, what else. The new official anticipated yield is 5,000 to 10,000 tons of TNT. Jaworski and I have both bet on 10,000. I think it's the first time we agreed on anything. Teller bet on 40,000 tons. He's always an optimist."

"Oppy?" Joe was supposed to find him, now he was at Trinity.

"Oppy predicts 300 tons. Three hundred tons is a dud. We're a little worried about Oppy."

Harvey and the plutonium core had arrived earlier that morning at a ranch house a mile south of the shot.

The rancher had been bought off and pushed out, but, except for Harvey's Plymouth and the four jeeps parked with their backs to the house and their motors running, the place still looked from the outside like any ordinary spread: barn and corral, a windmill to pump water and a cistern to hold it, a one-storey house within a low stone wall. Inside, the parlour walls were blue with a genteel white band below the ceiling line. The oak floor had been vacuumed and the windows sealed with plastic sheets and masking tape. All the furniture had been removed except the table, which was covered with brown paper. Working at Trinity, Harvey had already joined the two silver-plated plutonium hemispheres into one 11 lb sphere the size of a grapefruit. Dressed in a white surgical coat, rubber gloves on his hands, he was now filling holes on the sphere's shining surface with tiny wads of Kleenex, the fill-all of Trinity. Geiger counters conversed on the floor. Six silent men in lab coats monitored the counters, gave Harvey one tool and then another. The only person without a task was Oppy. A man six feet tall began to look strange when his weight got down to seven stone. Oppy's head seemed gaunt and swollen at the same time, too large for the neck that stuck out of the lab coat. His hands wrung a cold briar. Somebody had hammered a nail in the wall for him to hang his porkpie hat from, the same as in his office on the Hill. The hat was there, but Oppy seemed oddly out of place and miserable, not triumphant at all.

"Remember the Dragon," Harvey said although he hadn't looked up from the core when Joe came in.

Joe stayed back by the wall, which was a foot thick, making the room relatively cool, maybe ninety degrees. The plastic-covered window faced the idling cars, poised for flight in case of a mishap, in case of a slip of Harvey's hands. Joe's mission orders now that he was at Trinity were to stay with Oppy at all times and make sure the project Director survived any accident. Harvey gave the core a final polish with an emery cloth. "I gave away my clarinet."

"Too bad. You had great potential," Joe said. Harvey's Critical Assembly team followed his every move with the intensity of chicks watching their mother turn an egg. One of them put on the table long brass tweezers and a small, shockproof case studded with plugs. He unlocked the case and raised the lid. On a bed of foam rubber lay a pearl, a one-inch ball of platinum-coated polonium. This was the core within the core, an "initiator" which would emit a burst of neutrons in the first millionth of a second of detonation. "I think I'll stick to what I'm good at," Harvey said. He re-opened the larger core, propping the top hemisphere with his finger. With his free hand he picked up the brass tweezers and used it to lift the tiny ball. He had to place the "initiator" in its nest in the centre of the core, and the insertion had to be done in slow motion while the building radiation was monitored. Harvey blinked through his sweat, but his hands didn't falter. His finger prodded open the core a little more, a little more as the ball and tweezer advanced. The ticking of the Geiger counters rose like the pulse of excited hearts. Oppy looked like he was going to sway and drop.

" Those icy atoms up and down my spine ," Harvey sang softly. " The blue of ions when your eyes meet mine. A strange new tingle that I feel inside, and then that radiation starts its ride ."

Oppy's pipe hit the floor and spun across the boards. Harvey froze, fingers in the maw of the two hemispheres. "Joe, will you please take Oppy for a walk?"

Outside in the hot, dry air, Joe found his shirt had soaked through with sweat. Oppy sat on the low stone wall, hat on his knee.

"I suspect that before his flight, Icarus was throwing up. I wish we could just go into the mountains again, Joe, go riding again like we used to. I've ridden that horse of mine just once this year. I know they don't need me in there, but it's my test, Joe." He looked up at Joe. While the rest of Oppy had been worn down to bones and clothes, the blue eyes had the intensity of a man enduring pain. "I asked Groves for another week or just another four days. When this is over, we'll go riding."

"Sure."

Harvey called Joe inside. The core was closed and complete and sat in a lead-lined wooden box.

"He's been like this since he got here. Maybe he should go back to the Hill."

"It's his test," Joe said.

They carried the box on a litter out to Harvey's car and put it on the back seat. Joe took Oppy in the jeep and slowly led the way to the tower. The breeze of late afternoon was picking up. Dust devils whipped around the tower base.

Inside the tent, Foote and Jaworski had removed the polar cap at the top of the bomb and taken out a brass plug so that the plutonium core could be inserted. Harvey opened his box and attached the core to a vacuum cup. He tested the seal, then hooked the chain of a manual hoist on to the cup's eye. He pulled off his lab coat and kicked it away. Tested the seal again. Harvey looked like a plump and innocent boy, the sweat coursing off his belly, his fine blonde hair standing as if magnetized. Foote cranked the core up from its box. From a corner of the tent, Oppy and Joe watched Jaworski steady the core with a pencil as Foote swung it over the waiting bomb. Wind beat on the tent.

"One proper dust devil and a few grains of sand and we can put our symmetrical implosion into a pisspot," Foote said.

He lowered the core. One moment it hovered over the bomb like a moon above a larger body, the next it was descending by its chain into the bomb's interior. And stuck.

Jaworski waved his hand up. His moustaches had started to sag. Foote cranked up the core and lowered it into the bomb again. It stuck.

Foote cranked the core halfway out of the bomb, slipped the hoist's ratchet and painstakingly let out the chain again. The core made its slow downward passage, nudging lenses of high explosive as it descended.

And stuck. By a millimetre or so, the plutonium core was simply too big, or the hollow inside the bomb was too small.

"I don't believe this," Oppy said and stared first at the bomb and then at Foote. "It isn't possible. You measured wrong?"

The tent walls shook. Measured wrong? Wouldn't fit? Like a pair of tight jeans? Joe pictured anyone telling that to General Groves, and he could see every man was imagining the same scene.

Harvey laughed.

"It's the desert heat. The plutonium's hot, expanded. Grade school physics. Leave the core where it is, it'll cool."

It took five minutes, but the temperature of the plutonium and high explosive equalized and the core slipped meekly into place. Jaworski unsealed the vacuum cup, and as Foote raised the chain Harvey inserted a three-foot-long manganese wire down to the resting core to check its neutron count. Connected to a Geiger counter, the wire detected a cascade of ions, a noise like a hive. "I'm done." Harvey withdrew the needle. He paused at the hole as if he couldn't trust the moment, then slipped quickly out of the tent flap.