Casey was Jess’s little sister and she lived with Uncle Tim and Aunt Jean up here in the middle of the Scottish wilderness, having moved up a few months ago after Dad had died. They weren’t real sisters. Jess had been fostered, then adopted, aged seven, by the couple she came to know as Mum and Dad, when they didn’t think they could have children of their own. Then, less than a year later, Casey had turned up. By rights, Jess should have been jealous, but from the start she’d adored her little sister, and felt hugely protective of her, a feeling that had grown even stronger when first Mum, then Dad, had died.

The whole reason Jess had come up here from London was to see Casey and make sure she was settling in okay. And to be fair, it seemed she was. Unlike Jess herself, Casey was really excited about this canoeing trip, and she jumped into the front of the other canoe, taking her paddle excitedly from the old guy, while Uncle Tim got in the back.

The old guy grinned at Casey, his eyes twinkling. It was, Jess thought, the same old story. Everyone fell in love with Casey. She was just that kind of girl. She was blonde, bubbly, with a sweet cherubic face, a cute button nose, and a lively personality, but also enough smarts to know how to get round people, and make them do what she wanted without them realizing they were doing it. Although more than seven years separated them, Jess had always grown up in her shadow. Sometimes it surprised her that she wasn’t more envious of Casey, but only a few times had the fact that her sister got all the attention ever irritated her, and in truth, she loved her sister just as everyone else did. And now, with Dad gone, Casey was all she had left.

‘Okay, you’ve got my phone number,’ said the old guy, standing above them. ‘The mobile reception’s patchy along the river, but you’ll be able to get it in parts. The river’s running pretty slow at the moment, so you shouldn’t run into any problems but, if you do, just give us a call. Otherwise, we’ll meet you at the bridge near Tayleigh at five o’clock. That should give you plenty of time.’

Five o’clock? That was almost four hours away and Jess felt her heart sink. There were a hundred things she’d rather be doing than this. When she’d come up, she’d envisaged taking Casey shopping in Inverness, not hauling ass down some Godforsaken river in the back of beyond.

‘Have you got everything, Tim?’ yelled Aunt Jean from behind her, her voice loud in Jess’s ear.

Tim patted the rucksack beside him. ‘Food, drink, the lot,’ he replied, sounding as excited as Casey. ‘Are we all ready?’

‘I’m ready,’ shouted Casey, lifting the paddle above her head, two-handed, making the old guy laugh.

‘You’re going to have a great time, wee lassie,’ he told her, and gave their canoe a push so it drifted into the deeper water. ‘And you will too, lassie, if you let yourself,’ he said to Jess.

‘She’s from London,’ said Jean, as if this explained everything. ‘She’s not used to the great outdoors.’

‘I’ll be fine,’ said Jess wearily, forcing a smile as she sank her paddle in the water, while the old guy gave their canoe a push and they drifted slowly out onto the river.

And right into the beginning of a nightmare.

Five

20 days ago

MIKE BOLT WAS dreaming about his dead wife.

It was something he did more and more these days. The fact was he’d pretty much deified her. In death, she could do no wrong, which was why he’d never been able to hold down a serious relationship in the almost ten years since she’d passed away. He’d been engaged a couple of years back for a while to a CPS lawyer called Claire. He’d even moved her in to his place in Clerkenwell, and for a while he’d thought that she might finally be the one to get him over Mikaela. But in the end it hadn’t worked either. Claire did things that irritated him, things that Mikaela would never have done. She talked about her work all the time; she obsessed about her weight and kept going on strange, masochistic diets; and she didn’t like children. Bolt wasn’t a huge fan of kids either, but Mikaela had been, and she’d also been two months pregnant when she’d died. So, as far as Bolt was concerned, it reflected badly on Claire, and was yet another reason to end his relationship with her.

Since Claire had gone, Bolt had had a couple of other flings, including a recent one with a former colleague of his, Tina Boyd, which had been doomed from the start (Tina was far too much of a handful for him, and probably any man), but for the last few months he’d been resolutely single, giving him ample opportunity to fixate on Mikaela – something that he’d lost no time in doing.

In this particular dream Bolt was having, he and Mikaela were riding horses across a long lonely stretch of beach somewhere in France. Mikaela’s horse was galloping away into the distance, and looked to Bolt to be out of control, but Mikaela didn’t seem to care. The wind was blowing through her long blonde hair and he could hear her laughter fading away as she got further and further from his horse, which refused to go any faster than at a gentle trot even though he was yelling at it to get a move on. And then, as he watched, Mikaela disappeared from view altogether.

Which was the moment the windswept beach began to fade as an incessant ringing in his head drowned out everything else.

Bolt’s eyes snapped open and he sat up in the bed. His mobile was vibrating and bouncing round the bedside table. The clock said 05.46. As he reached over to pick up the phone, he paused to look at the photo of him and Mikaela that stood next to it. It was a shot from their holiday in Corfu two summers before she died, both of them tanned and grinning at the camera. Whenever he was in a relationship, Bolt would hide the photo away, sneaking only the occasional peek at it, but the moment he was single, it would be back on the bedside table so that he could wake up every morning to his memories. He knew it was bad for him to dwell as much as he did, but he seemed incapable of doing anything about it. Emotionally, he was trapped in a past that had ended almost a decade earlier, and the sad thing was, he probably always would be. Only one thing kept his mind off Mikaela, and that was work.

And it was work calling him now. Specifically, his long-time colleague, Mo Khan. And, even before he picked up the phone, Bolt knew what it was going to be about, because there’d only be one reason why Mo would be phoning at this time in the morning, although he hoped to God he was wrong.

Yawning, he pressed the Call Receive button. ‘You woke me from a beautiful dream.’

‘I’m truly sorry about that, boss, but right now that’s the least of our problems.’

Bolt felt his heart sink. ‘There’s been another one, hasn’t there?’

‘It looks that way. I’ve just had a call from a DCI Matt Black of Thames Valley CID. They’ve got a murder scene up in some woods between Reading and Basingstoke. A home invasion. Two dead, one injured. They think it might be the work of The Disciple.’

‘That’s three casualties. He usually only targets couples.’

‘It looks like he attacked the husband and his mistress, and the wife turned up and disturbed him. She made a dash for it, and although she got cut up a bit, and almost got hit by a car while she was running, she’s conscious.’

‘Is there anything specific that makes Thames Valley think it’s The Disciple?’

‘The MO’s definitely his, boss. No question about it.’

Bolt sighed and got out of bed, looking for some clean clothes. ‘Christ, this is all we need. The pressure’s going to be even more intense now. Who’s driving, me or you?’

‘I’m just about to get in my car now. I’ll be with you in twenty. You can sleep on the way down, have some more beautiful dreams.’