A massive wall of water burst through the headlands and surged across the bay. The wave moved so quickly that Hotaka only just managed to glimpse his uncle’s blue and white trawler slide over the top. He heaved a sigh of relief, but then gasped as the stragglers in the fleet were picked up like toys, tossed backwards and swallowed.

Barely half a minute later the wave roared over the breakwater that reached a little way out into the bay, powering on as though it didn’t even exist. It hit the marina and grabbed everything in its path – nets, buoys, traps, pots, boats, fuel tanks, gas bottles, machinery, the wharves, the sheds, the people. There were no exceptions; the wave took everything and hurled it all at the town.

Hotaka and Takeshi howled in horror. This was a monster like nothing they’d ever seen on TV or in films, or even dreamt of, an unstoppable harvester of death and destruction. It raged on, smashing through the marina wall. People were scrambling from the gridlocked vehicles lined up along the road skirting the harbour, but they didn’t have a chance. They were devoured.

Beautiful old buildings along the foreshore were ripped from their foundations and smashed to bits. Quaint houses and rows of shops were flung together in an enormous churning mess that surged on – a giant beast of chaos with an insatiable appetite, feeding as it flowed, gorging itself, grinding, crunching, obliterating all in its path.

The water surged into town, a thickening swill of death, blackened with oil and grime and the grey-green churning of the harbour floor. Voices rose from this roiling spew, cries and shouts and howls for help – victims writhing within the beast itself.

‘Nigete, run!’

‘Tasukete, help me!’

From where they stood Hotaka and Takeshi could look right across Omori-wan to the hills that rose in the west. But the sleet and snow had become so heavy that they could barely see the town centre, let alone their school. What they saw, though, was more than enough. The wave had reached the centre, its black tentacles slithering through streets, lanes and alleys in search of victims. The surge had slowed, but was still far too fast for anyone on foot.

The boys gaped at the scene of horror spreading around them like some visible disease. ‘People are dying!’ Takeshi shouted, pointing at the town. ‘Dying!’ There was anger and outrage in his voice. ‘We have to do something!’

‘But we told Abe-sensei we’d get help for her.’

‘What are you talking about? They’re safe on the hill. It’s down there that people are dying. They’re the ones who need help.’

‘I know, but what can we do?’

‘There must be—’ Takeshi choked on his words, his eyes darting about. ‘Yes. Over there,’ he yelled, pointing down to where the old people’s home had stood only minutes earlier.

Most of the building and its occupants had been washed away in the tsunami’s initial surge. A piece of decking was still standing, though, buckled and partly submerged. Five people clutched the railing at one end, hanging on for dear life.

‘Come on,’ Takeshi yelled, and raced down the hill, Hotaka close behind.

When they reached the place, the situation looked dire. The decking creaked and groaned, buffeted by swirling water, in danger of breaking away at any moment. Rescuing these people would be difficult. It was about twenty metres out to the decking; younger, fitter people could swim across, but these were old and infirm. They’d have to be helped. But how?

Among some debris, Hotaka found a length of thick rope, more than enough to bridge the gap. As he untangled it Takeshi secured one end to the stump of a sturdy bush.

‘That should hold,’ he told Hotaka, tying the other end of the rope around his waist. ‘We have to move quickly. If the water rises much more it could sweep away the decking.’

Takeshi was a strong swimmer, and soon reached the decking. He climbed up and bound the rope to the railing, tugging it tight. Then he took the arm of an elderly woman and yelled to Hotaka as he led her towards the edge of the decking.

‘I’m bringing her over. Meet me halfway.’

Even though Hotaka knew the water would be perishingly cold, it still took his breath away. The current was stronger than he expected, too, almost pulling his feet from under him. He met Takeshi and took charge of the old woman. She shook with cold and wailed like a frightened child, but Hotaka slowly edged her to shore as Takeshi went back for the next person.

The process was slow and difficult, made even more so by the old people, frail and frightened as they were. One of the men lost his grip as he entered the water; it took all of Takeshi’s strength to haul him back to the rope. Then the second-last person, a woman, lunged at Hotaka and clung so tightly around his neck that she dragged him under for a while. He was so exhausted after getting her to shore that he had to rest to catch his breath.

When he turned and started dragging himself out again he saw that Takeshi was in trouble. The last person, a big man, was struggling frantically and had to be hauled every inch of the way.

‘I can’t swim!’ he kept yelling.

As they drew closer Hotaka could see the exhaustion on Takeshi’s face. His friend was begging the man to relax, but it made no difference. Hotaka lunged forward, grabbing the old fellow away from Takeshi and was immediately pulled under by the man. He dragged himself by the rope, much of the time submerged, certain he would drown. But just when he thought his lungs would burst, his face broke the surface and he crawled to safe ground, hauling the man with him. Hotaka lay spluttering for a while, then rolled onto his back and stared up at the sky, thankful to be alive.

‘We did it!’ he shouted, half-gasping, half-laughing. ‘We did it, Takeshi.’

There was no reply.

Hotaka sat up and stared around. ‘Takeshi?’

His friend was nowhere to be seen.

Hotaka leapt to his feet and screamed, ‘Takeshi!’

There was no Takeshi, no sign of him. Just the length of thick rope swaying in the water – the silent unrevealing water.

‘Takeshi!’ Hotaka dived in and thrashed his way out to the decking, scrambling up onto it. ‘Takeshi!’

He scanned the swirling mess, frantically searching. Everywhere. Anywhere. Nowhere. Nothing recognisable. Everything a possibility, but that was all. A voice calling. A hand waving. A head bobbing. Real or imagined? Out there or in his mind? Or both? Nothing was real, everything was a living nightmare.

‘Takeshi!’

Hotaka glanced towards the old people. They hadn’t moved, all staring at him as if waiting for instructions. Were they stupid? Why weren’t they heading up the hill? Another wave could easily come.

‘What’s the matter?’ he shouted. ‘Move!’ He strode to the edge of the platform. It groaned and tilted more. ‘Nigete, get away!’

All moved except the big man who’d been saved last. He didn’t budge.

‘What’s wrong? Are you deaf?’ Hotaka screamed. ‘Nigete!’ The man still didn’t move. ‘You’ve got your life. What else do you want? Get out of here!’

But the man began shaking his head, at which a kind of madness gripped Hotaka. He screeched, shook his fists and stamped his feet, so infuriated that he didn’t hear the metallic scream. He saw the horror on the big man’s face, and felt the lurch beneath his feet.

He was still screaming as the whole deck lifted up and tossed him backwards into the water, then flipped over and slammed down on top of him.