One

He turned and there was the polished skull of a raptor lying on the ground. Tiny, basilisk, fragile. He picked it up, a weight that was almost not there. It was like holding an origami conceit. He inspected the boss and the bill and the eye sockets, turning the skull in his hands delicately, feeling its egg-shell thinness flexing beneath his fingers. He could feel the hot stare of intent yellow, smell the blood of its prey, so much of it gushing through these chambers that had it had crept like a stain through the porous bone, its own kill badge.

Jane lifted the skull to his face and breathed in the air that was trapped in the fossae of its nasal cavities. He thought he caught a flavour of what it meant to be wild, untrammelled. A killing machine, something designed solely for the purpose of death.

He got lost on the way back to the tent. He couldn't find it, no matter how often he looped back or measured his progress against the road and the lines of dead trees. He didn't call out. He lay down in the sand of a bunker, burying himself in it. At least he was sheltered from the night's breath. He fell asleep dreaming of the skull. How it was positioned looking away from him. The grind of spine as it rotated his head to look at him. Eyes behind the sockets, accusatory. Stanley's eyes, rendered by this alien juxtaposition into something freakish and chilling. The bill opened to howl his name and blood began to gush out. He put out his hands to plug it but there was no stemming its ferocity.

When he wakened, he smelled the copper of blood and saw that the tent was less than twenty yards away from where he had bedded down.

Aidan had rallied. He was eating dry Rice Krispies from the box, supplying his own snap, crackle, pop sound effects. The raptor skull didn't look quite so savage in the daylight and, after a moment's pause, he handed it to the boy.

'Keep it safe,' he told him. 'For luck.'

He saw Becky bite on some admonishment that she might have been considering. Aidan wouldn't have been put off; he was fascinated by the skull, once he'd established that the bird was dead, although it meant that Jane had to field a series of questions about the bird's skin and feathers and where they had gone and what, exactly, did decomposition mean?

They walked the A1 until lunchtime, when they stopped to eat. A blue shirt hung in the leafless branches of a tree. A brown shoe stood by the trunk, as if waiting for it to come down. Large, glittering worms hung and spun in the air: scraps of tape and insulating foam, and what looked like shreds of metallic paint.

Aidan munched his way through three hot dogs in brine, relishing the disgust on Jane's face. 'Look, I'm eating widgets,' Aidan said. Jane covered his eyes and pretended to be sick.

The wind brought the smell of the city to them. A foul fossil smell of oil and rendered tallow and cadavers and standing water. There was mildew in it, and something faecal; something old and defeated, like the smell you got when you opened the wardrobe of a dying grandparent who no longer combed his hair or brushed his teeth. It was the smell of capitulation.

The road was blocked.

'Holy fuck,' Jane said, his voice full of awe, both at the horror before him and the fact that he could still have the wind punched from him, there were still sights to be seen. Aidan looked up at him quizzically, perhaps about to ask him about the bad word, but he too was distracted. Becky simply stopped walking. She sat down in the road and bowed her head.

Jane told Aidan to wait with her, but he refused. Together they approached what was left of the airliner. The M25 stretched its arms out before them as if offering a hug, or a shrug, unspoken sympathy for the disaster it had witnessed. One engine remained, as far as Jane could see. Debris was spread all over the road and across much of a large field, north-west of Junction 1 of the A1 motorway road. Around two hundred yards away they could see the deep black gouges in the blacktop where the aircraft had hit. Perhaps the aircraft had tried to land on the A1. Perhaps it had just been battered down out of the sky by the fierce strike of incinerated air, a newspaper swatting a fly.

'It was a big one,' Jane said.

'How big? As big as a elephant?'

'Oh yeah.'

He pointed out the immense crippled landing gear. 'Look, see? Six wheels. That means it was a 777. Big plane. Big engine. If there were three of you inside standing on top of each other, you might just reach the top.'

'How many people could it carry?'

Jane looked around at the wreckage. Little remained of the fuselage. Curved aft sections. A portion of wing. A portion of the great tail. He didn't recognise the livery. Something from the Far East, most likely.

'I don't know. It depends on the route, I think. And the time. Three hundred and fifty, maybe. Maybe as many as five hundred. A little more.'

Aidan spread his arms wide. 'About this many?'

'Yes, that's about right.'