He drew his wife a little closer to him, and gazed out across the Atlantic. The sun was preparing to drop into the sea. The sky turned violet, wisps of cloud glowed pink on the horizon and little waves to lapped at the beach. Hooper thought about staying awhile. The highway would be busy right now, but in an hour or so they'd have a clear ride through to Southampton. It would only take twenty minutes to cover the fifty kilometres on the Harley. It seemed a shame to leave now.

Especially since after sunset Montauk Point was the perfect place for lovers, or so everyone said.

They picked their way slowly through the rocks. After a few paces they came to an area of flat ground, out of sight of the rest of the beach. Hooper was in love, and he liked the idea that no one could see them.

Never in a million years would he have guessed that two men in an underground bunker in Buckley Field were watching him from an altitude of 195 kilometres, as he kissed his wife, sliding his hands under her T-shirt and slipping it off, while she unbuckled his belt. Eventually they lay clasped together on their clothes. He covered her with kisses and Linda rolled on to her back. His lips roamed over her breasts, towards her belly, and his hands were everywhere at once.

She giggled. 'Stop that. It tickles.'

He took his right hand off the inside of her thigh and kissed her again.

'Hey, what are you doing?'

What was he doing? He was doing the things he always did – things he knew she liked. He kissed her lips but her eyes were fixed on something behind him. Hooper turned.

There was a crab on Linda's shin. With a little shriek, she shook it off. It landed on its back, then splayed its pincers and straggled to get up. 'Ugh! It scared me.'

'I guess it wanted part of the action.' Hooper grinned. 'Well, too bad, buddy, you'll have to find a lady of your own.'

Linda laughed and propped herself up on her elbows. 'Funny little thing,' she said. 'I've never seen a crab like that before.'

Hooper inspected it more closely. The crab still hadn't moved. It wasn't especially big – no more than ten centimetres long – and it was white. Its carapace glowed against the darkness of the rock. Sure, it was an unusual colour, but there was something else about it. Linda was right.

Then he realised. 'It's got no eyes,' he said.

'Oh, yeah.' She rolled over and crawled towards the creature on her hands and knees. 'Freaky. Do think something's wrong with it?^'

'I'd say it never had eyes.' Hooper ran his fingers down her spine. 'Just ignore it – it's not doing any harm.'

Linda picked up a pebble and took aim. The crab didn't flinch. She prodded its claws and pulled her hand back quickly, but nothing happened.

He let out a sigh.

'Come on, forget the stupid crab.' Hooper crouched next to her and prodded it. 'That's one laid-back crab.'

Smiling, she kissed him. Hooper felt her tongue wind round his. He closed his eyes, abandoning himself to…

Linda flinched. 'Darryl.'

The crab was on her hand. There was another behind it, and a third next to that. His eyes darted up the wall of rock that separated their hideout from the beach.

The black stone surface was covered with myriad armoured shells.

White eyeless creatures with pincers, row after row, as far as the eye could see.

There were millions of them.

'Oh, God,' Linda whispered.

The sea of bodies started to move. Hooper had watched smaller crustaceans scuttle about on the sand, but he'd always pictured crabs walking slowly and majestically. These were fast – so fast it was frightening. Like a tidal wave they swept towards them, their armoured legs clattering softly on the rock.

Stark naked, Linda leaped to her feet and backed away. Hooper tried to gather their things, but stumbled, dropping an armful of clothes. The crabs swarmed over them, and Hooper sprang back.

The creatures followed him.

'They won't hurt you,' he called out. But Linda was already scrambling over the rocks.

'Linda!'

She lost her balance, sprawling head-first on the rocks. Hooper rushed over, but the crabs were moving faster, surging past and clambering over them. Linda screamed, her voice high-pitched and panicky. With the flat of his hand he beat away the creatures as they marched over her back, scrabbling up his arms. She jumped up, panic-stricken, tugging at her hair. There were crabs on her scalp. Hooper grabbed her and pushed her forwards. He didn't mean to hurt her; he just wanted to get them out of there, away from the avalanche of creatures swarming over the rocks. But Linda tripped again, clutching at him and pulling him with her. He crashed to the ground and felt a mass of crab shell shatter beneath him. Sharp fragments dug painfully into his flesh. He lashed out. Hundreds of sharp feet scurried over his body. He saw blood on his fingers, and hauled himself up, dragging Linda with him.

Somehow they made it across the rocks and ran naked to the Harley. Hooper glanced back over his shoulder. From the raised ground around the lighthouse the entire beach was seething with crabs. They were rising out of the ocean, too numerous to count. The first wave had already reached the parking lot and was picking up speed on the even terrain. Hooper was running, tugging Linda behind him. His soles prickled with splintered shell, and slime coated his feet. He had to be careful not to slip. At last they reached the motorbike, leaped on, and Hooper pulled back the throttle.

They sped out of the parking lot and on to the open road, racing towards Southampton. The motorbike skidded dangerously on a slippery layer of mangled crab. Then they were out of the teeming mass and shooting along the tarmac. Linda clung to him. A van appeared from the opposite direction, an old man at the wheel, eyes wide in disbelief. It was like something out of a movie, thought Hooper – two people on a motorbike, without a stitch of clothing. He would have found it funny if it hadn't been so awful.

The houses on the edge of Montauk loomed into view. The eastern tip of Long Island was just a narrow strip of land, with the road running parallel to the coast. As Hooper made for the town he saw a sea of white crabs advancing from the left. They spilled over the bluff and marched towards the road.

He accelerated.

The white sea was faster.

It reached the tarmac just a few metres before the sign that welcomed visitors to Montauk. The road seethed. A track was reversing out of a driveway. Hooper felt the Harley skid. He tried to dodge the vehicle, but the motorbike was out of control.

Oh, no, he thought. Oh, please, God, no.

The truck rolled across the road, with the Harley skidding towards it. Hooper heard Linda scream, and wrenched the bike round. They slid past the front of the truck, missing the chrome-plated metal by a hair The Harley was still turning but Hooper steadied it. People were jumping out of their path. He took no notice. The road ahead was clear.

At full tilt they headed for Southampton.

BUCKLEY FIELD, USA

'What the hell's going on down there?'

Cody's fingers sped over the keyboard. He tried viewing the images with different filters, but all they could see was a light-coloured mass spilling inland from the ocean.

'It looks like a wave,' he said. 'Like a flicking big wave.'

'But there wasn't a wave,' said Mike. 'It's got to be animals.'

'What kind of flicking animals?'

'They're…' Mike stared at the monitor. He pointed. 'Look, right there! Zoom in on that. Cut it down to a square metre.'

Cody selected the area and zoomed in. The screen was filled with a mixture of light and dark pixels.

'Closer.'

The pixels expanded, some white, others in varying shades of grey.