'Hey, come on,' Paul said, leaning over the table and rubbing the side of her arm. 'You're a great mother, and you've done absolutely the right thing. You couldn't stay with Vernon just for Jack's sake, you know.'

'Yeah. I know all that. But still...'

'But nothing. And as for coming with me, well, you are doing me the most enormous favour, and I'm extremely grateful. This is really, really important to me and my family, and I couldn't do it without you. So - thank you.'

'I'm not only doing it for you,' she said.

'I know. But...'

He stood up and kissed her forehead, and Kate felt tears p.r.i.c.kle. 'I'm probably just tired,' she said, managing a watery smile. 'We had such an early start this morning, and I don't think I'm even properly over the jetlag. This has all happened so fast. Plus, I keep waiting for Vernon to somehow turn up, shouting the odds. I don't even dare switch on my cellphone in case there are dozens of furious messages from him but now I'll have to, won't I? I told Miranda to let Jack call me whenever he wanted.'

'Well, that's easily fixed. Just call her now and give her my mobile number instead. Jack can reach you on that.'

Kate looked grateful. 'OK. Good idea. We should get to Mrs. Bainbridge's by noon time to have a chat to her, if she's in, and then go and get some lunch afterwards. Then... um... where do we go next? Will we be staying up here?'

Paul blushed, very slightly, and Kate realized his train of thought was along the same line as hers: two rooms, or one?

'I suppose it depends on what leads we get out of Mrs. B, if any. And maybe we should stay for a night anyway, to give ourselves a break. We could ask Mrs. B if she knows any cheap and cheerful B&Bs nearby. If the worst comes to the worst, we'll have to sleep in the car.'

'Great,' said Kate, rolling her eyes. 'You certainly know how to show a girl a good time.'

'You bet I do, honey,' Paul replied, winking at her, and Kate felt herself growing hot in all kinds of places.

'Come on,' she said briskly, 'let's. .h.i.t the road.' Otherwise, she thought, I'm going to march over to the motel next door to this service station and book us into a room right now, and forget Mrs. Bainbridge...

Two hours later, Kate and Paul had parked the car in the car park of a small tennis club, across the road from a pretty thatched cottage which hopefully belonged to Leonard's widow. On the courts next to them some elderly people were playing doubles in a fairly desultory fashion, and Kate inspected their faces carefully, in case she recognised Mrs. Bainbridge. She had wracked her brains, but couldn't remember anything about her, although she'd met her once or twice as a kid.

'I wonder if she'll remember me?' she said aloud.

'I'm sure she will, if they were such good friends of your parents,' Paul replied, switching off the engine and unfastening his seatbelt.

'It's quite weird, seeing someone who knew my folks so well. I suppose it'll be for me a bit like it was for Sarah's mother when we turned up at her place. I hope she's there.'

'Only one way to find out,' said Paul, climbing out of the car. 'Let's go.'

They crossed the road and walked up to the front door; Kate nervously, Paul more a.s.sertively. He seemed full of energy, raring to go.

Kate rang the bell. 'What are we going to ask her?' she whispered. 'Where do we start?'

'Leave it to me,' said Paul confidently. 'It'll be fine.'

There was no answer. Paul pushed open the letterbox and peered inside. 'No sign of anyone in there.'

'There's a car on the drive at the side,' said Kate. 'Maybe she's in the garden.'

'I'll go round the back and have a look. She might not have heard the doorbell. You stay here and ring again, in case she was in the loo or something.'

Paul vanished down the path at the side of the house, past garishly flowering purple-and-pink fuchsia bushes, as Kate pressed the bell again. The house was neatly kept, with shiny bra.s.s furniture on the door, and even the glossy painted panels looking as though they were regularly wiped clean. Kate idly inspected her distorted reflection in the flap of the letterbox, wondering again if Mrs. Bainbridge would recognize her as the skinny little girl she'd been at their last meeting. She tried to remember if Mrs. Bainbridge had been around during those hazy weeks when she, Kate, was in hospital after the fire, when Leonard had arranged for her to go to Harvard. She didn't think so - although everything was such a blur from that time.

Still no answer from inside. Kate stood back and looked up at the upstairs windows, but the net curtains were white and fresh and undisturbed. What an anti-climax, if they'd come all this way and Mrs. B. was on holiday. Or had moved abroad...

Kate thought she heard raised voices coming from the back of the house. She c.o.c.ked her head and listened harder. She could make out the sound of Paul's voice - not what he was saying, but the tone of it: pleading, almost outraged; and shrill, almost hysterical replies. Uh-oh, she thought. Guess he found her, then.

She was just tentatively making her way past the fuchsia bushes when Paul appeared, red in the face with anger, stalking down the path towards her.

'Come on, Kate,' he said brusquely, grabbing her hand and almost dragging her towards the gate. 'We're wasting our time here. She's f.u.c.king nuts.'

'How the h.e.l.l did you manage to upset her like that in two minutes flat?' Kate asked, when they were back in the car. Paul laid his forehead on the steering wheel in a gesture of frustration and defeat. He shrugged.

'I can't understand it. She was at the bottom of the garden, digging a vegetable patch. I probably gave her a fright I sort of came up behind her. I think she must be quite deaf, because I was calling her name all the way down the lawn, but she didn't respond, so I kept moving closer, until I tapped her on the shoulder...'

Kate groaned. 'No wonder she was scared, if you sneaked up behind her.'

'I didn't b.l.o.o.d.y sneak!' Paul retorted. 'What else was I meant to do? I tapped her on the shoulder, she jumped and held the garden fork out in front of her like she was about to impale me on it, and I tried to rea.s.sure her, but she wasn't having any of it. She's a game old bird, I'll give her that.'

'What did you say to her?'

'I just said that we were here because we wanted to talk to her about her late husband, and she went mental. I had to back away I mean, I really thought she was going to lunge at me with the fork. "You won't get away with it!" she kept shouting. "Leave now otherwise you'll regret it!" I think she must be doolally. I was trying to get her to listen to me saying about you, and that she knew your parents, but by that stage she was just yelling I don't think she even heard me. So I turned around and left.'

They looked at each other hopelessly. 'Now what?' Kate asked. 'Perhaps I ought to try.' She just about managed to refrain from saying that she ought to have been the one to try in the first place she was sure she could have done it in a less confrontational manner. 'There's no point in knocking again, she won't answer, will she? And I'm sure she'll have gone back into the house. She's not likely to have stayed out in the garden if she's all that upset. I don't want to go sneaking round the back and risk wigging her out again.'

'I was not sneaking!' Paul reiterated defensively. He looked so like Jack, when Jack was in trouble, that Kate couldn't help smiling.

'We'll just have to wait till she's calmed down. Why don't we go and have a pub lunch, and come back later?'

'OK,' Paul said. 'Sorry I messed it up. What an idiot, eh? Talk about a bull in a china shop.'

Kate hugged him, slightly self-consciously. 'Don't worry. All is not lost. Let's go and eat. There was a nice-looking pub back there on the main road.'

Two hours later, after ploughmans' lunches containing slabs of cheese the size of small bricks, Paul and Kate walked back along the road towards Mrs. Bainbridge's cottage, and Paul's car, in the tennis club car park.

'I am so full-up,' said Kate, tasting pickled onion in her mouth, and feeling her pint of lager sloshing around in her stomach as they marched along the verge.

Paul laughed, his mood restored. 'I've noticed that about you: you're either starving, or stuffed.'

'Yes, well, you'd think I'd be used to large portions, having lived in the States. But that ploughmans was enough for four grown men.'

'I like your appet.i.te,' he replied. 'I can't stand girls who constantly fuss about how many calories they're consuming. It's so uns.e.xy.' He grinned at her, and she reached out and squeezed his hand. She felt unaccountably happy - despite the encroaching indigestion.

'Let's wait in the car for a while. We'll be able to see if she comes out, and we can nab her then. She can't shut the door in our faces if she's outside, can she? And hopefully that way it'll give her enough time to recognize me and not flip out.'

Paul squeezed Kate's hand back again, and pretended to frown. 'Wait in the car? Won't that be, like, really boring, with nothing to do?' He let go her hand and gently caressed the back of her neck, holding the pa.s.senger door open for her as he did so.

'We could play I-Spy,' said Kate, grinning at him as she climbed in.

'Or,' Paul said, getting in the other side and leaning slowly towards her, 'perhaps we could think of something else to pa.s.s the time.'

They kissed, both of them smiling through the kiss. 'Sorry if I taste of pickled onion,' Kate mumbled, but Paul just kissed her again. 'If you do, then so do I,' he replied when they surfaced.

'That's all right then. Kiss me again?'

Half an hour later, they were still kissing. Paul had had to switch on the engine and lower the electric windows, since the car had become almost completely steamed up.

'We'd make rubbish private investigators, wouldn't we? Bin Laden himself could've been in and out of that cottage ten times, and we'd be none the wiser,' Kate said, coming up for air. She was painfully aware of how turned on she was. She was dying to touch him, but didn't dare. It had been so long since she'd kissed anyone including Vernon that she couldn't even remember the protocol for heavy petting. Perhaps she ought to wait till he touched her first?

'Don't worry. I've been keeping one eye open,' Paul replied.

Kate tutted. 'And there was I, thinking you only had eyes for me!'

'Isn't one eye good enough?'

'No. I'm very demanding. And s.e.x starved.' Kate slid her hand further up Paul's thigh. It was no good. She just couldn't wait any longer, she had to feel his erection. It felt absolutely wonderful, and they both sighed with pleasure.

'That's very impressive,' she whispered, rubbing it through his jeans.

'I don't think those two are quite so impressed,' said Paul, s.n.a.t.c.hing her hand away too late, as two elderly ladies in tennis whites walked past the back of the car, looking disgusted.

'Ooops,' Kate giggled, heady with l.u.s.t, and relief that he hadn't recoiled in horror at her forwardness.

'We'd better stop, otherwise I'm going to rip all your clothes off here and now, and not only will we never get to talk to Mrs. B, but we'll get arrested....' He dropped his voice, '.... And then I won't be able to make you come at least four times tonight, because we'll be in separate cells getting told off by the local constabulary.'

'Is that what you've got planned for me, then?' said Kate, feeling like a teenager again.

Paul leaned across to her, moving his own hand up between her legs. He nodded solemnly. 'Oh yes,' he murmured, and Kate thought she might just come on the spot.

'But first,' he announced briskly. 'Business!'

Kate groaned.

'She hasn't appeared. Her car is still there. It's been - ' he looked at his watch - 'over three hours since I did not sneak up on her, so I'm sure she'll have recovered by now. Why don't you go and ring the doorbell? It's worth a try. I don't think I can sit here any more without having s.e.x with you.'

'You've got a point. OK. You wait here, and I'll go and see if she'll let me in.'

CHAPTER 24.

John Sampson was standing on the site of the CRU, where Kate and Paul had stood just twenty-four hours earlier, when his mobile rang. It was the phone that was only ever called by one person: Gaunt. He hesitated before answering it. He had been enjoying the sweet memories from his last night at this place.

'Yes?'

'About time. I thought you were never going to answer.'

Sampson waited for Gaunt to continue.

'Any luck tracking our quarry?'

Sampson knew that Gaunt, who spent most of his life these days in laboratories, enjoyed the espionage, the spy thriller stuff that added a dash of colour to his days. He pretended not to, but Sampson could hear the excitement in his voice. He told Gaunt what he'd found so far.

'In other words, she's got away.'

Again, Sampson stayed silent, clenching his jaw muscles and taking slow, calming breaths.

Eventually, Gaunt said, 'You'd better get back here to the base. How long will it take you?'

'Not long.' Sampson hung up and took a last look around the housing estate. She had been here. The use of the word 'quarry' had been appropriate. He was the hound and Kate the fox; he swore he could almost smell her on the air.

Security at the base was strict, aimed at keeping out not just the wrong people but the organisms they carried; the bacteria, viruses and parasites that made their homes on and inside human beings. Inside the doorway, Sampson, who had been through this procedure many times, stripped, showered and washed his skin and hair what there was of it with an anti-bacterial solution. Next, a doctor wearing a mask checked him over, examining him and asking him questions to make sure he hadn't noticed any signs of infection recently. Had he suffered from any cold or flu-like symptoms? How about headaches, stomach pains, bowel or bladder problems, fatigue, nausea, dizziness? What about s.e.xual partners? Had he had unprotected s.e.x? Had he visited any of the following countries? He answered a terse no to everything; they knew he hadn't been abroad since his last visit. After the examination he put on clean underwear, a T-shirt and trousers, then slipped on a pair of soft shoes. Finally, he was allowed into the interior of the building.

Gaunt met him in the corridor. They walked past the rooms where Sampson had seen the girls the Vietnamese woman and the Serbian prost.i.tute not long ago. They weren't there anymore. The rooms were empty, scrubbed clean; all traces of their previous occupants gone.

They reached Dr. Gaunt's office. He gestured for Sampson to sit down, and took a seat at the opposite side of his desk.

'I saw you looking into the empty rooms. You took a fancy to our little Serbian, didn't you?' He smiled, displaying yellow teeth. 'Nothing left of her now, I'm afraid to say. Incinerated.'

Gaunt opened a drawer and took out a gold chain with a heart-shaped locket on the end. He held it up, and it glinted as it rotated back and forth.

'Oh, except this. This is all that's left of her.'

Sampson recognised the locket that the Serbian prost.i.tute had been wearing.

'Rather nice, I thought,' said the doctor. 'I removed the photo of the child that was in it.' He dropped it back into the drawer. 'It's mine now.'

Sampson concealed his contempt for Gaunt's need to keep souvenirs of the people he'd killed. 'Why did you ask me to come here?'

The smile vanished from Gaunt's face. 'I wanted to let you know that we're very close.'

'Close?'

'To finishing what we started a long time ago. Thanks to your trip to Oxford we've had a bit of a breakthrough in the lab and the final part of the puzzle has been solved.' His smile reappeared, wider and dirtier than before. 'This is very good news.'

Sampson groped for something to say. Eventually he came up with, 'Congratulations.'

'Thank you. There are just a few final tests to conduct, and some other preparations, making sure everyone's in the right place and so on. But I would expect matters to be concluded during the next few days.' He leaned forward across the desk. 'Which means it's critically important that n.o.body and nothing gets in the way.'

'You mean Kate?'

Gaunt raised an eyebrow. 'On first-name terms, are we?'

Sampson's face remained impa.s.sive. 'I wasn't sure whether to call her Carling or Maddox.'

'Well, she's Maddox now. Although we should never have given her the chance to reach her next birthday, let alone get married and change her name. f.u.c.king Bainbridge and his sentimentality, letting her go like that. She's a loose end.'

Sampson had an image of himself tying the loose end up. Handcuffing her, perhaps.