There was a certain definition, an edge to the dance when Joe returned. One black and white clown had a camera and was taking a picture of Foote. Then aimed it like a gun. The clown in sunglasses pretended to be blind and stumbled with a stick along the front line of the tourists, pinching a skirt here, feeling a blouse there. In the dancers' line, women giggled. Slide. Half-toe. Turn.

A third clown slipped out of the circle. One pillow was tied to the back of his loincloth and another was strapped to his belly. A fur moustache was stuck to his lip, gold stars to his shoulders, and on his head he wore an Army officer's cap with a paper star. Ponderously he walked clockwise to the dancers, so that they passed in review for him. When he added a twitch to the pillow on his ass, the impersonation of General Groves was complete. The other clowns bowed and salaamed. Anna Weiss laughed, but Oppy looked pained.

A Buick four-door drew up in front of the mission. Fuchs was at the wheel and Augustino was with him. Cars weren't allowed that close. When a tribal policeman went to the car and waved it on, a rear window rolled down and Joe saw the Indian Service rider called Al. The car stayed.

The clown in sunglasses produced a small firecracker. Another clown took it, another clown blessed it and a fourth clown put it on the ground and pretended to light it while the clown-Groves raised binoculars to his circled eyes to watch. All the other clowns except the one in sunglasses put their fingers to their ears.

Nothing.

A second match was tried. A third. A fourth.

A dud.

One after another, clowns inspected the firecracker and passed it on until it was with the clown-Groves, who studied it through his binoculars and gave it to the clown in sunglasses, who turned and presented the firecracker to Oppy. The crowd closed in to see. The dancers had never stopped and the singers hadn't ceased their chant, but their eyes were on Oppy, too. Joe had never seen Oppy blush before. The clown in the sunglasses got on his knees and begged.

"Go ahead, Oppy!" Foote shouted. "Be a sport!"

In the car, Augustino pointed to the clown in glasses.

Anna handed Oppy a cigarette lighter. The other clowns fell to their knees to plead. Oppy rescued a smile and lit the fuse and threw the firecracker into the air, where it exploded with a puff and a bang. Whether the firecracker happened to come at the end of the morning dance or was the signal for it to stop, the circle of dancers abruptly broke and dispersed for lunch. The clowns went off in single file, holding on to the long black tails of each other's loincloths, through an alley on the north side of the plaza which was out of bounds to tourists.

Fuchs' Buick was gone.

"You should be proud," Jaworski said and shook Oppy's hand. "They're dancing for our victory and success."

"Wasn't there some element of menace?" Teller suggested.

"Nonsense," Foote said. "Oppy, you played your part beautifully, even modestly."

Oppy returned Anna's lighter.

"Anna, I have to leave."

"I'll stay. They're more alive than you said."

Augustine had joined the group. "They certainly are alive. Can we talk, Dr Oppenheimer? You and me and Sergeant Pena?"

The parking lot was an oat field beaten into a cloud of dust. More cars were arriving than leaving. Augustino's jeep was next to the gray Army sedan Joe had brought Oppy in. Joe still couldn't find Fuchs' Buick.

Augustino asked, "The ones in the black and white greasepaint, Sergeant, are they idiots or traitors?"

"The clowns?"

"Whatever," Augustino said, "that was a serious breach of security. They singled out Dr Oppenheimer here in public view and identified him with explosives. Any outsider with a background in physics had to notice him and Teller. The imitation of the general was in the worst possible taste. What is the religious purpose behind that?"

"You'd have to ask them, sir."

"I'd love to. Who are they?"

"I don't know, sir."

"A tribal secret?"

"I guess so, sir."

"There's a great deal you're not telling me these days, Sergeant. They dance again?"

"This afternoon, sir."

"Same clowns, same people?"

"Yes, sir."

"Then I think it would be wise for you to drive the Director back to the Hill now, before there's another incident. You do agree, Dr Oppenheimer?"

Oppy stared back at the plaza.

"I thought we had good relations with these people. I thought we were friends."

"What other incident, sir?" Joe asked Augustino.

"Follow me," the captain said after a pause.

All traffic leaving the lot for the highway had to pass over a narrow cattle guard. Joe stopped for incoming cars while Augustino's jeep went ahead. As always when they were alone, Oppy sat up in front with Joe. He tapped on the dashboard impatiently, as if a herd of morons were holding him back. Word of the dance had spread. From Santa Fe open buses dropped off tourists, who hurried on foot across the guard. A short figure with a camera and binoculars round his neck Joe recognized from the bar of La Fonda, the New Yorker named Harry Gold.

Joe dug into his pocket and gave Oppy what looked like a wire-mesh button.

"That's a microphone Augustino put in your house while you were gone. It's time you knew what's going on around you."

Oppy held the microphone up to the light of the windshield as if he were examining some mildly interesting artefact.

"It was hidden," Joe said. "It wasn't put there for your protection. He's watching you, he's after you."

"I know."

Oppy's voice had fallen to a whisper. He turned the tiny microphone over and over.

"Tell General Groves," Joe said. "Tell the general that his head of Intelligence thinks you're a Red spy."

"The general knows." Oppy looked at Joe with a clear gaze of resignation and contempt. It was an inner look, a meditation. He put his hand out of the open window and dropped the microphone on to the dirt outside. "You can't help me, Joe."

"You're in charge of the most important lab in the war and you're scared of a captain? They can't do anything without you. You're the goddamn bomb."

"It's… a temporary situation."

The cattle guard was clearing. Augustino's jeep waited far up the road.

Joe got out. "Then I'll help Augustino."

Oppy slid behind the wheel and asked, "Help him?"

"He wants to know who those clowns are. It takes an Indian to stop an Indian, right?"

"Joe -" Oppy started to protest. He began again. "Joe, twenty more days. After Trinity, no one can touch us."

Joe made a wide circuit of Santiago on his way back. Fuchs' car was gone, probably halfway to the Hill by now. The Indian Service riders, Billy and Al, were drinking beers in the back of a tribal police car in an alley. All around the plaza Indians ate fried bread on their roofs. Under the plaza cottonwood in an island of shade, tourists ate sandwiches. Waxed paper floated over the ground on waves of heat.

15

Around the shaft of sunlight that came down the ladder to the kiva roof, three clowns repaired their black and white stripes from Mason jars of body paint. Two clowns without caps rested on the wall benches. The last stood in the shadow of the corner to drink a Coke and piss into a pail. All turned to the side door as Joe came in.

He hadn't been in a kiva for almost twenty years. Outside, the kiva of the clowns was a plain adobe house. Inside, though, the walls were painted with shapes that seemed to hover in the dark. Snakes. Swallows. Stepped mountains and red and white clouds. The zigzag lightning slats of a dismantled altar stood between Spanish chests of prayer sticks and dance wands. The floor was beaten earth, and had the traditional hole that led to the centre of the earth. The clowns themselves seemed dislocated, white blocks, bars of black. Even so, Joe saw that one of the clowns without a cap, a clown with loose gray hair, a heavy belly and spindly legs was Ben Reyes.