Not unless you were in a hurry, Louise thought.

'Not unless you were in a hurry,' Jackson said.

'Don't start thinking,' Louise warned him.

'Look at the facts,' he said, ignoring her advice. 'The woman has definitely gone AWOL, but whether voluntarily or against her will, that's the question.'

'No shit, Sherlock,' Louise muttered.

'Something bad has happened to Dr Hunter,' Reggie said stoutly. 'I know it has. I keep telling you the man in Mr Hunter's house was threatening him, he said something would happen to "you and yours". He wasn't joking.'

'I'm just kicking the wheels on this,' Jackson said, 'but maybe the husband's covering for her?'

'Why?' Louise said.

'Dunno. He's her husband, that's what spouses do.'

'Do they?' Louise said. 'What's she called?'

'Who? What's who called?'

'Your spouse.'

'Tessa. She's called Tessa. You would like her,' he added. 'You would like my wife.'

'No I wouldn't.'

'Yes you would,' Jackson said.

'Oh,just shut up.'

'Make me,' Jackson said.

'Stop it,' the small voice of reason in the back seat said.

'She left everything,' Reggie said. 'Her phone, her purse, her spectacles, her inhaler, her spare inhaler, her dog, the baby's blanket. Plus she didn't get changed, the first thing she does is get changed and the men who were threatening Mr Hunter said he would never hear from them again if he didn't come up with the goods. And the aunt doesn't exist! WHAT MORE EVIDENCE DOYOU NEED?'

'Get her to breathe into a paper bag or something, will you?' Louise said to Jackson.

*

'But,' Marcus said, 'does it have anything to do with Decker or not? Is it just a coincidence that he appears at the exact moment that she disappears? And what? He just walked away from the train crash?'

'He hasn't actually appeared anywhere,' Louise pointed out. 'He's the invisible man.' 'Decker,' Jackson murmured, gazing thoughtfully out of the car window. 'Decker? Why do I know that name?'

The absence of Decker, the presence ofJackson. As if they had changed places in some mysterious way. Jackson had lost his BlackBerry in the train crash and mysteriously acquired Decker's driving licence at the same time. Had he unknowingly swapped with Decker? Was Decker the man who rang Joanna Hunter's phone when Louise was in the house yesterday morning? He had been looking for ']0', not Joanna, not Dr Hunter. Is that what she had said to him when she visited him in prison -Call me Jo? What else did she say to him?

'What else did you lose?' Louise asked Jackson. 'Credit cards, driving licence, keys,' Jackson said. 'There's an address book in the BlackBerry.'

'So your whole identity, basically. What if Decker's using it? You get the driving licence of a Category A prisoner with a warrant out against him and he gets you -upstanding citizen -so-called -credit cards, money, keys, a phone. The last person who phoned Joanna Hunter on Wednesday called on your phone, your BlackBerry, so perhaps it was Decker. He phones Joanna Hunter and then she disappears. Neil Hunter says she left at seven but we only have his word for it. Maybe she left later, after the phone call. And if she did drive away -somehow or other, not in her car, not in a rental -and she wasn't driving down to see the aunt then where was she going? To meet someone else? Decker? Did he catch the train to Edinburgh because they had arranged a meeting? He gets derailed, literally, he phones her afterwards and she goes off to meet him.'

'And then what?' Marcus said.

'That's the bit that worries me. What about CCTV, there must be cameras up where she lives, lots of rich people live on that street, and-' 'Back up a minute,' Jackson said. 'Why are you so interested in this guy Decker? I don't understand.' 'Yes,' Reggie said. 'Who is Andrew Decker? And what's he got to do with Dr Hunter?'

Sorry, kid, Louise thought. She hadn't wanted to be the one to tell Reggie aboutJoanna Hunter's past. As she expected, this information made Reggie even more vocal. (,Murdered? Her whole family?') The girl was a terrier, you had to hand it to her. She wasn't even related to Joanna Hunter and yet she seemed to care about her more than anyone else. Louise couldn't imagine Archie feeling like this about her.

'Jesus,' Jackson said. 'Of course -Andrew Decker. How could I have forgotten that name? We were on manoeuvres on Dartmoor. We were called in to search for the missing girl, the one that got away.'

'Joanna Mason,' Louise said. 'Now Joanna Hunter.'

'And now you have to look for her again,' Reggie said to Jackson.

'Just because something bad happened to her once doesn't mean it's happened again,' Louise said to Reggie.

'No,' Reggie said. 'You're wrong. Just because something bad happened to her once doesn't mean it won't happen again. Believe me, bad things happen to me all the time.'

'Me too,' Jackson said.

'You're worried that this Decker's going after Joanna Hunter?' Jackson asked Louise. 'It seems unlikely, I've never heard of anyone doing that.'

'To tell you the truth I'm beginning to worry that Joanna Hunter is going after Andrew Decker.'

'On the other hand,' Louise said.

They were parked on the forecourt of a service station. Marcus and Reggie were in the shop buying snacks and Jackson had slipped into the front passenger seat. He was giving off heat. Louise wondered if he had a fever or ifshe was imagining it because of her own overheated state. She wanted him to hold her, she wanted to let her bones melt, even if for a moment. She never felt like this with Patrick, never wanted to stop being Louise, but sitting here on the brightly lit forecourt she wanted to give in, leave the battlefield. Was there a way of keeping him this time, locking him up in a prison, a box, a safe, so he couldn't get away again?

'On the other hand what?' he prompted.

'Neil Hunter, Joanna's husband, is hardly above suspicion. For all we know he's done away with her himself. And the baby. Maybe she was leaving him and he lost it.'

'It happens.'

'On the other hand ... he also knows some quite interesting people.'

'Interesting?'

'What we in the trade call "criminals". Some guys from Glasgow we've been hearing rumours about for a while. A guy called Anderson. He's trying to get into town, muscle in on some legit businesses. Private car hire being a particular favourite apparently.'

'Mini-cabs?'

'Yeah. And amusement arcades. Health clubs. Ropy beauty parlours. Guess who owns all of those?' 'Neil Hunter?' 'Bingo. One ofhis amusement arcades burned down last week and there's been some other stuff.'

'Stuff?'

'Technical term. We were looking at Hunter for wilful fire-raising but now I'm seriously beginning to wonder. What if Anderson's threatening Hunter's family? Kidnapped, Reggie keeps saying and she's been right about everything else so far. Bizarrely.'

'You and yours. Think about it. Sweet little wife, pretty little baby. Do you want to see them again? Because it's your call. That's what Reggie said.'

'You've got a good memory for an old man.'

'Lot of rote learning at school. And I'm forty-nine. Younger than your spouse, I believe. Do you want to see them again? Do you think they're being held somewhere?'

'And the aunt was just a red herring. A wild goose. A way of throwing anyone offwho was worried aboutJoanna Hunter's sudden disappearance,' Louise said. 'The ironic thing is that her husband needn't have bothered, Decker leaving prison gave Joanna Hunter a really good reason not to be around. Neil Hunter should never have gone down the aunt route.'

'Good theories,' Jackson said. 'How are we going to prove or disprove them?'

'We're doing nothing. Just me. I'm the real police, you're just a waster. Basically.'

'Thanks.' He reached his hand out and took hers and said, 'I really did miss you, you know.' Her mouth went dry and her heart slipped into overdrive as ifshe had some kind ofvirus and she thought about starting the engine and driving him away to the nearest hotel, barn or lay-by, but Marcus and Reggie were already barrelling out of the shop and she only just had time to reclaim her hand before they bundled back into the car, bringing in a draught of cold night air and ripping open crisp packets.