The gardens were small, a mere twelve hectares, a green and brown patchwork oasis in the sprawling brick and tarmac desolation that loomed over the fence and licked its lips and that would at long last swallow them up in 2002. The operators had overextended with the new eco-greenhouse to the north of the car park at a time when visitor numbers had plummeted due to the opening of the brasher and bolder theme park five minutes drive down the A-road, and even with a petition and a cake sale, Nature Land had gone forever. The council weeded it and kept the model river flowing until 2004, when even the open days had stopped. Then, in 2008, the estate had gone up and there was as little trace of it all as the sailor that had gone overboard on Mr. Laurence's yacht fifteen years later. That was a sad affair indeed, but not as sad as the diappearance of the garden.

Even the ticket booth had been a treat. It was a thatched hut by a little pond where you could feed the ducks, and the interior was an Aladdin's cave of plastic dinosaurs and drawstring bags full of gems. Mr. Laurence had always left there with some piece of tat or other, despite his mother's protests. Then they would go on to the long brick building beyond the rose garden, and read all about the new treasure over cups of tea and hot chocolate, and maybe even a slice of cake if it was early afternoon and it wasn't too far past payday.

Mr. Laurence had told all this to his team, and not one face showed the slightest interest, no matter how much he was paying them. He wondered if each of them had their own garden in the wilderness of their memories, or if their heads really were just stuffed full with the facts and figures and technical specifications that they ceaselessly craved. Either way, that's all they wanted from him, not the reasons why. So he toned it down for the rest of the briefing.

The gardens were L-shaped, with the model river running north to south through the main axis. Little signs there told you about each concrete block or steel lattice which marked the main buildings of the town. Most of their larger counterparts were gone too by now, blasted so everyone could forget and move on. East of the river were the compost bins, where each lift of a lid brought a dizzying array of smells which should have been foul but which always seemed fresh, despite the rot. There was the model compost heap too, with the giant ants with glowing eyes. The goat enclosure was through a gate on the other side, and then the Japanese garden with the blossoms where you could slip in autumn if you weren't careful. There was the alpine rockery, and the little forest with the fairy-houses in the clearing in the middle, and the bamboo maze with the throne of the kings in the middle, and the model World War Two house with the dig for victory veg plots, the main duck pond, the climate-friendly flower beds with the signs about a future that seemed a million years away, the sand pit with the digger that foreshadowed what would come when the rollercoaster drew the new kids from the climbing frame at the back of the lily lake, and the hill where you could see it all at the end, or the beginning too if you got there late and had to choose which part you wanted to see most. And all of that even before they built the greenhouse, with steel domes like a flying saucer and the stands of cacti like something from another planet, that Mr. Laurence thought then he would never see in the wild.

Then he looked at the team and saw that he was rambling again. They only wanted to know where.

"But it's all important," he protested, because it was. It was important because he didn't know until he'd solved the riddles.

That's why they couldn't be surgical here. That's why seventeen families were cleared to grind their homes to mortar dust. The protests were deafening until they were told the settlement details. Then they told the papers that Mr. Laurence was a gentleman instead.

And now where once was a living room with a leather sofa and bookshelf and fish tank, Mr. Laurence himself traces the invisible outline of the herb beds. It is the first time he has left America in seven years, the first time he has flown without bodyguards or even a mobile phone, and the last time he will visit the town in which he was raised. Around him, caking his trouser cuffs, only mud and ground brick. A deeper waste within the urban desert.

But he remembers.

He pauses suddenly upon a cracked paving flag, a wrinkled frown dissolving to calm. The team of builders around him are now sure something else is cracked too.

"This is where the hunt began," he told them somberly. They all nod, because Mr. Laurence is generous.

Previously, he has begun the hunt three times.

He walks on, to where Sammy Squirrel had hidden the acorns beneath the stub of an outhouse wall. Only then it was the entrance to the bamboo maze, swaying and whispering tall in a summer breeze. The helicopter pilot says something to the cook next to him, who, wishing to keep his position, only stares.

Mr. Laurence walks and, in tailored suit and hand-me-down school jumper at the same time, bends to read the next clue, tucked behind a wooden mushroom at the edge of the rockery, within the broken pipework of a toilet. His joints complain, but time is not important now.

"And then we see the mole in the power station," he tells his chief assistant, by his side with a bottle of water and sunglasses in hand. The sunglasses will not be required. This town is always grey.

He means, of course, the model power station, the crudely painted slab of concrete by the stream he called a river. It still exists, as part of an embankment in a playground in a tiny park three miles away. Mr. Laurence neither knows nor cares of its fate, because he can see it, poking out from behind a digger. A real digger.

He only got this far twice. The first time he began the hunt, his mother had told him it was time to leave for supper. He had cried, because Sammy Squirrel hadn't yet given up his prize. But father would have been angry, and he didn't want that.

He reads the next clue. Half of it is obscured by the warning sign it has merged with, but he knows all the same. On he walks, entourage in tow, along the edge of the duck lake, to where Harry Hedgehog pointed out the final acorns. A youth screams an obscenity through the protection of the chainlink fence. Two assistants give chase. Mr. Laurence doesn't even hear, because he is thinking how lucky he is to get this far. The only other time, he had had to stop to go and feed his sister. He was old then, and he had responsibilities.

Disappointment had clouded his thoughts on the half-hour trudge home, through the frost, and yet he had known he would be back.

Back he was. And horribly, impossibly old, though maybe his committments had eased back a bit these past few years. He could afford them to. But one thing kept coming back, again and again. The most important thing.

The metal plaque by the compost heap featured a jovial butterfly by the name of Billy. Billy lived where the Graingers had lived three months before Mr. Laurence had come into their lives, where a little Billy was looking forward to starting school in the autumn. The name was a coincidence.

And now, Mr. Laurence reaches an impasse. This is the test.

A group of teens watch, arms folded, from the corner of the blockaded estate. A builder spits, glances at his watch. It is growing dark. He eyes Mr. Laurence's Rolex and wonders where he would be if he had all this money. A duck flaps overhead, quacking into the gloom.

Mr Laurence looks about the ruins, and for the first time in a long time, he thinks for himself. All his divisions of technicians in Nevada cannot help him now. He wanders through the detritus, scuffing his shoes in the dirt. The polish is scraped clean off the leather. His mother would be furious.

So would Sammy, if he fails now. But he doesn't. Fifteen minutes later, he walks to the raised edge of a foundation, points with one bony finger, and says one simple word.

"Here."

The drills are brought forward. Concrete screams to fragments. Beneath, there is soil, and worms, and a box.

Despite the pain in his crippled back, Mr. Laurence stoops to retrieve it. It is only the size of a shoebox, and there are letters on it, but the paint is too flaked to read them. He opens the box, and looks at what is inside.

It has taken him hundreds of thousands of pounds, and a horde of babbling lawyers, and three years, to take this look. Or perhaps it has taken him sixty years. But Mr. Laurence is quick. There is not much to see in the box, but he has seen enough.

In agony, he falls to his knees, and puts the box back in its earthern cocoon. He motions for the incredulous builders to cover everything all over again. Then he stands and walks for the gate, telling his driver to bring the car around. His aides rush to help him, but he marches on strong. There is a spring in his step, and a boyish gleam in his eye.

Mr. Laurence leaves for Los Angeles on the 7:10 am from Heathrow. He is never seen in this country again.

* * *

It is not, however, the last time the thing in the box is unearthed. It is revealed fourteen years later, when Mr. Laurence is just a statue in the square and Jake has just returned from a disastrous trip to the theme park down the road. His mum is furious with Dad, who spent the entire day grumbling about how it had all lost its charm since he was last there, how he wouldn't allow the kids on half the rides because they were falling apart, and how the whole bloody thing needed shutting down. But it wasn't Dad who spoilt the fun.

Jake retreats to the garden to avoid the growing storm in the bedroom. He finds solace in digging for treasure in the vegetable patch, which Dad set up for him after that trip to the gardens in Hampshire last year when they were on holiday. A sudden shriek pulls his eyes towards the wall behind, but the window has nothing to show. It is a new build, Jake's house, sturdy and pretty and much bigger than where most people at school live, even though Jake's family are poor. Ryan's dad says the whole estate was built by a mad businessman who tore everything down just to build it up again, just before Jake was born. But Jake never believes anything that man has to say.

The animal voices are reaching a crescendo when Jake's tunnelling fingers touch something rough, deep down below the potatoes. Eyes wide, he digs outwards, heart thumping, soil itching down his chest, until he can pull the whole thing from its hiding place. He grins even before he opens the box. Because he was right; he knew there had to be a chest of gold around here, he just had to believe, and now he can go on all sorts of adventures across the sea in a big white yacht and tell Dad all about it when he gets home.

* * *

He still missed it.

It wasn't a chest of gold. But he kept it all the same. It went to their next home, and Mum's house after that. Then uni, and then, silly as it was, to the hospital in Scotland when he got the job. A good luck charm, he supposed. And then, when it was time to get out, something changed. It didn't seem right for it to go. Something was pulling it back.

It was a stupid day. He hadn't known what had come over him, frankly. But he supposed he had to. Something inside told him it was right.

The house looked the same, apart from the windows were blue. There was no car in the drive. The gate to the back door was unlocked. The vegetable patch was still there, just where he had left it all those lives ago. It was a flower bed then, actually, and it would be underneath the new gym now, according to an old college buddy, but it was still there at the time.

And everything he did that night just felt right.

"What are you smiling about?" Kate asked.

"Hmmm?" he looked around, and he was on the balcony of his villa, high out over the glimmering Atlantic on a summer's night thirty-two years later. With a start, he saw that is was almost midnight. He had a lot to think about, important things like how Tabby was going to get down from the airport in the morning, and what they were going to wear for the wedding.

And he wondered if it was still there.

"I said," said Kate, amused. "What are you smiling about?"

But he wasn't smiling now. He was just thinking.

"Oh, nothing," Jake said. "Nothing at all." He looked out across the waves. Then, calculating, he went inside.