'We'll put it right bit by bit.' She had a hard time explaining why the house meant so much to her. Paul had fantasized so often about being free to travel, it seemed odd that her instinct now was to put down roots. 'We're all packed in so closely together.'

'What's that?'

'You can see rows and rows of Victorian terraces from up here. You'd think we would know more about each other. How do we all manage to live such separate lives?'

'Come on down, the van's here.'

Paul's brother had brought over their clothes. Kallie had been shocked to see how easily her world could be packed into a few boxes. She suspected that Paul thought it was rather cool. He didn't like the idea of becoming encumbered by belongings. She had agreed at the time, but being here changed everything. There was something about the house that made you want to draw the curtains and never go out.

She loved being up on the roof, feeling the first spackles of evening rain on her face, looking down at the ten gardens, five from the houses on her side of Balaklava Street, five more from the road beyond, grouped together like a densely cultivated park, divided by strips of fence and low brick walls. She counted rowans, wild cherry trees, a small-leafed lime, holly, crab apples, London plane trees, hornbeams, several ponds, sheds, clothes lines, a conspiracy of gnomes. The gardens harboured the interior life of the neighbourhood. Kids didn't play on the streets any more, but the gardens were still safe, protected by terraced fortresses. She knew she would come up here often on summer nights, the way a cat climbs a tree to better survey its territory.

'It smells damp,' Neil sniffed. 'Needs a lot of work.' He picked at a corner of wallpaper in the hall and lifted it, running his finger across the powdery grey plaster. 'All this will have to come off.'

'It's fine for now,' Kallie told him, protectively smoothing the paper back in place. Neil worked for a mobile-phone company in the city, and wanted to be twenty-five for ever, even though he was in his early thirties. He treated his girlfriends like his cars, replacing them with more roadworthy models whenever they showed signs of mileage.

'That's the last box out,' he told her. 'There wasn't much to unload. How are you going to fill the rooms?'

'Self-assembly stuff, until we can afford something better.'

'It'll have to be flatpack to go down this hall.' Neil had a warehouse apartment with porterage, but the open-plan design had made it virtually impossible for anyone to stay without being in the way.

Paul went off with his brother to buy him a thank-you beer, so Kallie spent her first evening in the house alone. The carpets were filthy. She vacuumed them as best as she could, then set about washing out the kitchen cupboards. Plastic buckets filled with hot soapy water and disinfectant began to make the place more inhabitable. The old lady hadn't intentionally kept a dirty house, but she had clearly been unable to manage by herself. At least the electricity was back on, although it didn't extend to all parts of the house; the ancient wiring needed replacing.

There were odd noises outside: a ceanothus rattling with fresh rain in the garden, dead laburnum leaves dropping on to the yellowed roof of the leaking lean-to conservatory. Inside, too, the pilot light of the central-heating system flared up with a pop that made her jump, pipes ticked as steadily as grandfather clocks, floorboards creaked like the decks of a galleon. The basement light switches didn't work, and it wasn't worth trying to clean by torchlight.

A dead woman's house-worn cups and saucers, a drawer full of odd items of cutlery, another filled with string, bags, three-pin plugs and out-of-date discount vouchers, perished rubber teatowel holders from the seventies. Alien smells in the cupboards-packets of cardamom, juniper, custard powder, spills that were bitter and blackly sticky. Brown L-shaped marks on old linoleum where something heavy and ferrous had once stood and overflowed.

At ten-thirty she sat down in the ground-floor lounge to unpack linen and the handful of chipped china ornaments that had belonged to her grandmother. The street was preternaturally quiet, but now she could hear something. Setting down an armful of sheets, she rose and listened.

The sound of running water.

A steady susurration of rain, cataracts rushing through gutters, swirling into zinc funnels, precipitating through plastic pipes, racing across the bars of a drain. The crepitation was steadily rising to a crescendo.

She climbed the stairs to the floor above and walked into the second bedroom: no light bulb in here. The damp wood of the window frame had swollen so much that she couldn't budge it. The sound was softer beneath the roof, so it couldn't be loose guttering. Collecting her torch from the hall, she clicked it on and ventured into the basement. They would take out the non-supporting walls, she decided, repair the conservatory and bring more light in from the raised garden. The bathroom was absurdly large for the house. She supposed a parlour had been converted, yet it seemed odd to have had a parlour with only a single tiny window, high and crossed with bars, little more than a skylight looking out at street level.

Now she heard the sound quite clearly, running-no, rushing rushing water. It seemed to be coming from the right-hand adjoining wall. She hadn't met the people on that side. Heather had told her that their names were Omar and Fatima. What could they be doing that would make such a noise? It wasn't a tap, more like a set of them, all turned on at once. The sound had volume and depth. Coupled with the noise of the heavily falling rain, the sense of precipitation seemed to enclose the house entirely. water. It seemed to be coming from the right-hand adjoining wall. She hadn't met the people on that side. Heather had told her that their names were Omar and Fatima. What could they be doing that would make such a noise? It wasn't a tap, more like a set of them, all turned on at once. The sound had volume and depth. Coupled with the noise of the heavily falling rain, the sense of precipitation seemed to enclose the house entirely.

She shone the torch around the bathroom, and wished she hadn't. The fittings were cheap, a bilious shade of avocado that had been popular in the seventies. Only the bath was white enamel, and there was a good chance that it had feet, those French ball-and-claws that could look nice if they were cleaned up. Unfortunately, the whole thing had been boxed in with corrugated hardboard. She thought of her parents' house and remembered the craze for boarding over bannisters, sinks, door panels, any decoration that smacked of Victoriana. The house had probably had a dozen makeovers, each according to the prevailing taste of the times, each leaving a residue of personality in a crust of paint.

The Swiss army knife she had used on the packing cases was still in her back pocket. Cross-legged on the cold parquet floor, she unscrewed the six chrome-topped pins holding the bath's front hardboard panel, then dug the tip of the blade under its base. The board groaned as she flexed it, then split and came loose. She bent back the sheet until it lifted free, and was horrified to find that she had released hundreds of tiny brown spiders from their penumbral home. They scattered in every direction, over her legs, across the floor, up the walls, fleeing the torchlight. She leapt to her feet and shook out her hands in revulsion, dusting them from her clothes, feeling the tickle of legs everywhere, imagining more than she could see.

Jumping out of her jeans was the best idea, but scattering the spiders with bright light would have been better. She headed for the safety of the bare bulbs in the hall, leaving behind the churning noise of water. This, This, she thought, she thought, is what owning a house is all about. It's going to take some getting used to. is what owning a house is all about. It's going to take some getting used to.

10

THE UNDERGROUND MAN

May could hear something odd. It sounded like 'We are the Ovaltinies, happy girls and boys . . .' But of course it couldn't be; that radio jingle had surely vanished before the Second World War. He glanced at the new mobile phone on Bryant's desk and realized that the music was emanating from the earpiece. Arthur was even humming along as he fussily rearranged books on the mantelpiece. After all these years, he still had the ability to make May feel as if he was going mad. How the hell did he do it? More to the point, how did he bend radio waves from the past to transmit them through modern technology?

'Can you hear anything unusual?' he asked tentatively.

'I was thinking,' replied Bryant, failing, as usual, to answer a simple question. 'This fellow, this friend of yours, he's simply selling his services, no?' He poked longingly at the bowl of his pipe and eyed the No Smoking notice above his partner's head, reluctantly returning the briar to his top pocket. 'Academic information is a valuable commodity. I don't suppose the Museum of London pays very much. You can't begrudge him earning a little freelance.'

'My dear chap, I don't begrudge him anything. Far from it,' said May, as Longbright cleared a space on the desk and set down two mugs of strong Indian tea. 'The city wouldn't survive without its grey economy. I don't even like him. He's an arrogant bore. I just want to know what he's up to.'

'Even someone as stupid as Raymond Land will notice that a lecturer coming into a chunk of money hardly warrants sending two new recruits to sift through his rubbish bins. He could have won a bet on a horse, or have taken on a second job as a minicab driver.'

'Raymond's in the building,' warned Longbright. 'His golf's been cancelled because of the rain. Don't let him hear you call him stupid again.'

May waited until the sergeant had returned to her office. 'You don't understand, Arthur.'

'Then explain it to me.'

'I've known Gareth Greenwood for years. I'm surprised you haven't run across him, because he does guided walks too-the Late Victorians on alternate Friday evenings, Port of London first Sunday morning of the month. Surely you must cross over each other.'

'There are hundreds of guides, half of them unofficial,' said Bryant testily. 'I don't know them all. Do go on.'

'Greenwood is a brilliant academic with a Master's degree in early modern history. It's his wife who's worried about him. Monica called me a few days ago to tell me he'd taken an assignment through someone he met at the museum. He's being paid a considerable amount of money to perform some kind of illegal task, half up-front, half when it's completed. It's dangerous, too; he made out a will last week.'

'How does she know all this?'

'He's an archetypical academic, vague and rather remote-you could fire a gun while he's reading and he wouldn't notice. She dropped him off at the Barbican last Friday and realized he'd left some papers in the car, so she went after him. He was being met by some dodgy-looking character who was handing him wads of used notes and giving him instructions about what he had to do. Gareth's been in trouble before, you see. It wasn't his fault the first time, he was just a little naive. A friend of one of the museum's patrons offered him a rare piece of London sculpture. Greenwood didn't check its provenance or he would have known it was stolen. Outdoor statuary was never registered very strictly. It's only in recent times that the collectors' black market for large items has opened. The statue was one of a pair of Graces that had stood on Haverstock Hill for over a century. Greenwood had walked past it every day on his way to the Tube, but didn't recognize it when it was offered to the museum. His colleagues were sympathetic, and did what they could. Well-meaning academics have a history of unwitting involvement with fraud, blackmail and robbery. Whatever one might think of him as a person, Greenwood's one of the finest experts we have in this city-I'd hate him to make another mistake. He refuses point-blank to discuss this new business with his wife, and she's very worried.'

'So you asked Meera and Colin to go through his bins. Really, John, you're giving Raymond Land ammunition to take back to the Home Office. Couldn't you just have had a quiet word with him?'

'No, that wouldn't be possible,' said May uncomfortably. 'We were sort of rivals, and he's still a bit, you know, angry with me.'

'No, I don't know. What sort of rivals?'

'Well-the lady he married. I sort of met her first, and meant to break it off when she met Gareth, but neither of us got around to telling him, and then it sort of came out at a bad time.'

'Wait a minute, all this is about a woman?' Bryant fought hard to stop himself from laughing. 'What is it with you and married women? How long ago was this?'

'June 1978.'

He tried to prevent it, but the laugh escaped. 'That's over twenty-five years ago. You're not telling me he still bears a grudge.'

'Academics are capable of bearing grudges until the day they die. Obsession is in their nature. Anyway, we're not exactly being worked off our feet here, Arthur. I want to keep Mangeshkar and Bimsley busy. You know that if no work gets sent our way, the Met will end up using us on their cases by default, and when that happens the unit will be closed down for good.'

'They wouldn't do that. They approved the rebuilding programme in record time.'

'It would have happened anyway, because this site is valuable police property. Have you heard talk about a new style of police shop for the Camden area?'

'What do you mean?'

'It's one of the Home Office's pet ideas, a drop-in community centre staffed by casually dressed officers who liaise with local community leaders. And it'll sell products licensed to the Metropolitan Police, to interest the kiddies. That's what they're saying this place is going to become, some kind of Disney police store, just as soon as they've got us out.'

'Raymond wasn't happy about my involvement with Ruth Singh,' reminded Bryant, 'so we can hardly afford to have your lecturer-'

'It took them just a few minutes, Arthur. Meera found something. Look.' He flattened out the crumpled receipts. 'Greenwood just spent several hundred pounds on climbing equipment- high-tech stuff.'

'Perhaps he's taken up mountaineering.'

'Don't be daft, he's in his sixties and has a bronchial condition.'

'Well, I don't know. Is it really any business of yours?'

'He has some specialist classified knowledge. The kind of knowledge that could be open to abuse.'

'I thought he taught history.'

'I was thinking of his particular field of interest. Rivers. Specifically, the underground rivers of London.'

Bryant's interest was aroused. 'That's different. The culverts still run through very sensitive areas. Under Buckingham Palace, for example, and virtually under the Houses of Parliament.'

'Really? I thought they had all dried up long ago.'

'Not at all. The entire subject is open to misinterpretation, of course. It's a murky area of London interest; not only are the size, geography and number of the city's rivers up for dispute, but there is very little left to see, and no accurate way of comparing the present with the past. Consequently, one ends up tracking filthy dribbles of water between drains and across patches of waste ground.'

'Then why bother studying them at all?'

'Because just as the old hedgerows shaped our roads, so did the river beds. They created the form of London itself. They are the arteries from which its flesh grew.'

'Since when were you an expert?' asked May, surprised.

'I was going to do an overground guide tour tracing the route of Counter's Creek. That one's followed by a mainline railway line all the way from Kensal Green to Olympia, Earl's Court and the Thames. We studied quite a few, but abandoned the idea because of the difficulty of getting groups around the obstructions. The Westbourne river still surfaces as the Serpentine, you know. Many of the original river beds are mixed in with the Victorian sewer system now. There's something undeniably magical about the unseen parts of the city, don't you think? The roofs and sewers and sealed public buildings, the idea that a different map might emerge to chart previously unimagined landscapes.'

'I agree up to a point. But if there's nothing left of these rogue rivers, I don't see why someone would pay my old rival for information about them.'

'I didn't say there was nothing left. Most of them were bricked in. The best-known missing river is the Fleet, which starts on Hampstead Heath, going down through Kentish Town, diverting past us to St Pancras, then to Clerkenwell and Holborn, and out to the Thames just past Bridewell. It was also known as the Holebourne, or the stream in the hollow. They used to say it was a river that turned into a brook, a ditch and finally a drain. The Smithfield butchers chucked cow carcasses into it, and it was used as a toilet and communal rubbish dump for centuries, so it kept silting up and becoming a public health hazard. I think it was finally bricked over in the mid 1800s, but that's the point-most of the rivers ducked underground at various locations and were provided with brick tunnels, but that doesn't mean they dried up. Look at the Tach Brook, for example. It's still there, running underneath car parks and public buildings in Westminster. When I was a nipper, I used to climb down the viaduct and muck about beside the water that flowed out into the Thames from Millbank. Underground engineers still have to be wary of such channels, because they know their excavations could be destroyed by them.'

May pulled some papers from his drawer and threw them across the desk. 'Monica gave me this. Apparently, Greenwood is our top underground man. He's mapped them all out in his time, and that's only a partial list.'

Bryant scanned the list of evocative names. The Westbourne, Parr's Creek, the Roding, the Slade, the Tyburn, Mayes Brook, Hogsmill, the Crane, the Peck, the Ravensbourne, Hackney Brook, the Falcon, the Effra, the Neckinger, the Walbrook, the Wandle, dozens of other smaller tributaries.

'They run from Hampstead to Acton to Bromley to Barking,' May added.

'What do you expect? The city's in a basin and the water drains down.' Bryant spelled it out as if talking to a particularly inattentive child. 'River beds criss-cross the whole of London in a grid, around and underneath and sometimes even through some of the most sensitive buildings in the city. Some of them are connected to the sewers, which means they tap directly beneath government properties.'

'Here's the list of stuff Greenwood's purchased so far. Monica found it in his jacket.'

Bryant dug out his reading glasses and examined the sheets. 'This equipment is for climbing down, not up. Look at these items: high-powered torches, thigh-boots, pipe-clamps, hardly any ropes. This other receipt is a pharmaceutical treatment for rat bites. Looks like someone's hired him to get into the remains of an underground river for some dubious purpose, possibly to enter private property.'

'You think they might be planning to tunnel into the Bank of England, something like that? Wouldn't it be rather an outmoded notion in these days of computerized security?'

'Just because it hasn't been attempted for a few years doesn't mean it's outmoded, John. Think about it; someone has searched out an expert in the field who has a blotted copybook, and is proposing a venture that involves purchasing safety harnesses and weighted boots. I'm not saying that your cuckold has any knowledge of his client's real intentions, but he's refusing to tell his wife because he doesn't want to compromise her safety, which suggests he knows something.'

'I was planning to confront him with the evidence and warn him off, you know, as a friend,' said May.

'You said yourself he's not a friend, so why should he take your advice? Besides, I have a better solution.'

'What might that be?' asked May, dreading the answer.

'We can find out what he's up to, and stop him from doing it. It's a clear security issue. Raymond would have no option but to sanction the case.'

'Arthur, please don't do anything that would get us into trouble. We don't need it right now. We have to start playing by the book.'

Bryant's rheumy blue eyes widened in innocent indignation. 'I'm surprised at you, John. When have I ever got us into trouble?'

11

THE HEART BENEATH

Kallie sanded and undercoated the front door before applying a rich indigo gloss to the wood. She had repainted the bedroom and put up some cheap curtains, working her way down a list of chores, but felt as if she had barely scratched the surface. She hadn't lived in a house since her parents were together. She was crouched in the hall, trying to thump the lid back on the paint tin without crescenting her palms, when Heather walked past laden with shopping bags.

'How are you getting on?' she asked, peering in. 'Isn't Paul giving you a hand?'

'He's been called up to Manchester,' Kallie explained. 'He's still waiting to find out if he has a job. I thought I'd get this done before it started raining again. I don't like the look of the sky.'

'I don't suppose he'd be much help anyway. He's never been very practical, has he?' Heather wore full make-up and was dressed in a smart black suit and heels, hardly shopping attire. She was never casual, or even relaxed. 'Still, it's very good of you, doing all this yourself. I wouldn't know where to begin.'

'It's a case of having to. I used up my savings securing the house. There's hardly anything left over for fixtures and fittings, and nothing for renovations. God knows what will happen if Paul is made redundant.'

'It's still better to invest in property, darling. Look at what's happening to pensions. George lost a fortune in Lloyds, but luckily he has his own business these days. Has anybody told you about the party tomorrow night?'

'I got a note through the letterbox yesterday from the couple who live at number 43.' She straightened her back with a grimace. 'They're not holding it just for us, are they?'

'No, it's their son's tenth birthday, and Tamsin thought it would be nice for you to meet the neighbours, get to know a few people.'

'What are they like?'

'Oh, public school and a bit dim, but friendly enough and well-meaning. They communicate almost entirely through the boy, dote on him a bit too much, really, but she can't have any more children so he's become very precious to them. Actually, they always take our milk in when we're away so I can't complain. The child's called Brewer-an extraordinary choice, but it seems everyone has to come up with a novelty name these days.'