There were some men who set out to do a job – to find a man, or build a house, or push a railroad through; to break a horse, or learn how to use a gun, or farmland – with a single-minded concentration that excised anything else. They did it. And they never stopped along the way to think about another path: they just pushed ahead to what they had promised themselves.

Azul could understand that.

He expected Baum’s answer.

‘I saw,’ said the German. ‘But it don’t make no difference. I took a contract, an’ I’m gonna keep it. Hell! In my line of work you gotta do that. I back out on a feller, an’ he’s gonna come after me. It ain’t worth makin’ enemies.’

‘I’m one,’ said Azul. ‘I’ll kill you, if I can.’

‘You don’t get the chance,’ said Baum. ‘I ain’t gonna give it you.’

By the time the horses were saddled the rain had started. The big black cloud was coming down and the prairie was dusted with the heavy spots of the shower preceding the storm. Baum tied Azul’s hands to the saddle again and strung Dumfries’s horse behind. The bounty hunter took the lead, his own pony linked to Azul’s.

By noon the storm was on them. The wind got wilder, and the sun got hidden behind a massive bank of cloud. Lightning danced all around, and overhead there was thunder like the drumming of cannons. The rain built up from a spattering of drizzle to a steady downpour, then took on the character of hailstones.

The horses’ heads drooped, soaking manes lashing against dripping necks. Both men were drenched. It was impossible to see more than a few feet ahead.

Baum called a halt.

They were in a wide gulley, the split something like twenty feet across; the walls four feet above their heads. The bottom was already filling up with water so that the horses plodded through a turgid miasma of sticky mud, their hooves dragging with each step; slowly; ploddingly.

Baum turned his pony towards the high ground, following a shallow flank of sandstone that lifted towards a low ridge.

Azul kneed the gray stallion behind, dragging Dumfries’s mount behind him.

They reached the ridge and followed the sodden trail along to where an earlier flood had cut a cave into the sandstone. It was around twenty feet high and fifteen wide: deep enough that all three horses could find shelter.

Baum dismounted and hobbled the horses. Then he lifted Azul down and stared around the cave.

‘You think we’re all right here?’

‘Don’t you know?’ Azul stretched his legs. ‘You never been in a flash flood before?’

‘No.’ The German shook his head. ‘What happens?’

Azul shrugged, his mouth smiling, though his eyes stayed cold.

‘You get rain like this, the gulley fills up. It rises. It comes down like you never seen water before. It could fill this place.’

‘We’re high enough,’ said Baum. ‘We should be safe.’

‘Maybe,’ said Azul. ‘Wait and see.’

Baum went out to the mouth of the cave and stared down at the gray water that was filling the line of the gulley. It was high as a pony’s chest now, a floating scum of driftwood and dead animals bouncing over the roiling waves. Pieces of wood, tumbleweeds, drowned rabbits, two coyotes floated past; all dancing on the frontal wave of the flood.

‘Jesus!’ he said. ‘I never seen anything like that before.’

His attention was caught by the horrible magnificence of the churning water, his eyes fixed on the tumbling waves that shifted from greasy gray to pure yellow, and then to sandy foam and black.

Azul climbed to his feet, drawing the shard of glass from under his belt.

He ran forwards, lifting his bound hands so as to drop them around Baum’s neck.

The German heard him coming and began to turn, but the half-breed’s arms dropped like a gallows’ noose about his throat, fingers plucking viciously into the sides of the neck as the rope binding Azul’s wrists together cut under the chin and the sharp-edged glass cut into the bounty hunter’s neck.

Baum choked and drove a foot down hard on to Azul’s moccasin. The half-breed ignored the pain, lifting his other leg up in a savage blow that drove a knee into the German’s coccyx. Baum screamed as the tail of his spine broke and shattered inwards, the agony doubling his body over so that he forgot the pain in his throat.

Azul was lifted up, his bound hands still clutched over the windpipe. Baum folded to his knees, reaching up to grasp the half-breed’s arms and swing him in a wide, flailing circle, above his head.

Azul felt his hands come clear of the bounty hunter’s neck, then felt his back land heavily on the rain-slickened rim of the cave. He kicked out, smashing both feet against Baum’s knees.

The German went back, arms still spread wide from his grip on Azul’s arms. The half-breed wriggled round and planted a foot hard into the bounty hunter’s face.

Baum’s nose broke, twin gouts of blood bursting from his nostrils.

Azul kicked again, the second blow snapping of chips of broken tooth and shreds of lip flesh from Baum’s mouth.

He reached up on his knees as the bounty hunter slumped back, right hand fastening on the butt of the Colt. He stretched forwards, bound hands clutching for the gun. And fastened them over Baum’s big fist. At the same time he rammed a knee into the bounty hunter’s groin.

Baum screamed, a high-pitched yell that was compounded of agony and frustration. Azul kicked again, and saw the gun fall clear of the man’s hand.

It pitched outwards, sliding over the rim of the cave to land on the ledge above the roiling water.

Baum lifted his hands and brought them down, fisted, against Azul’s face. Stars danced through the half-breed’s mind, and then a fresh pain churned through him as Baum smashed one knee upwards into his stomach. He gagged, tasting vomit in his mouth, and then both the bounty hunter’s hands slammed against the sides of his neck, and sparks of sickening pain lanced through his mind.

He felt himself shoved away.

Was suddenly aware of nervous hooves drumming against his body. And knew that Baum was gone.

He came upon his knees in the empty cave.

Grabbed a stirrup and climbed to his feet.

Saw the bounty hunter’s saddlebags on the sandy floor. Saw his own beside them.

And snatched the familiar bulk of his own gun from the leather satchels.

It was difficult to cock the pistol with his wrists lashed together, but he did it. So when Fritz Baum came back into the cave he was ready.

The bounty hunter was soaking wet. His hat was gone, and his cropped hair was plastered flat over his skull. His mustache was draggled in streamy lines against his snarling mouth. His face was dripping, water falling from his heavy eyebrows into the slitted hollows of his eyes.

He saw Azul and saw death looking at him.

The half-breed squeezed the trigger of the Colt.

Felt the familiar buck of the gun against his hands.

Saw Baum’s face explode into fragments of bloody flesh.