‘Were there? That’s a shame.’

‘Some tourists staying at Pilsbury saw your car.’

Naden shrugged. ‘It hardly matters. As long as you realise Sally had nothing to do with it. I wouldn’t have involved her in something like that.’

‘How did you know she would keep insisting it was the right day?’

Now Naden laughed. ‘I take it you’re not married, Detective Sergeant?’

Cooper swallowed. ‘No, I’m not.’

‘It was obvious. Well, take it from me, when you’ve been married for a few years, some things become all too predictable. You don’t need to be able to read minds to work out what your partner will say. Sally has become very easy to predict.’

His tone of voice seemed to contradict the sense of his words. Cooper detected something deeper that Naden wasn’t saying, some aspect of his relationship that wasn’t on the surface.

‘But why do something so drastic?’ he said. ‘Why take the risk? It doesn’t make sense.’

‘Doesn’t it?’ Naden looked at the ground, as if contemplating the distance of the fall. ‘Sally is very sick, you know. She’s in a lot of pain most of the time.’

‘No, I didn’t know that.’

‘We’ve been together for so many years. It’s funny how nothing else seems to matter when you know someone’s going to die very soon. You consider all the things you’ve ever wanted to do, that you ought to do but have never dared to because of the risk to your liberty and reputation. And you start to think, Well, why not?’

Cooper nodded. That was something he could definitely understand. For months after Liz had been killed in the fire, he’d driven around the steepest roads in the Peak District late at night thinking, Well, why not?

‘I think that’s why Sally thinks about murder a lot too,’ said Naden. ‘She once told me that the best way to kill someone and get away with it is to lure them on to a high place and push them off. As long as there are no eyewitnesses, it’s impossible to prove forensically whether they were pushed or just fell.’

‘I’m not sure that’s true,’ said Cooper. ‘It depends on a lot of factors. For one thing, you’d need a good pretext to get someone into that position.’

Naden’s footsteps clanged on the metal walkway. The sound reverberated around the empty shed. And bounced off the hard concrete floor below.

‘Oh, it’s not that difficult,’ he said.

Diane Fry and Luke Irvine entered the factory through the same door Cooper had used. Outside in Hartington, the last few fireworks were spluttering to a halt after a spectacular finale.

Fry kicked against a pair of wellington boots standing by a doorway and crunched through a pile of dusty leaflets on the floor.

‘What a mess,’ said Irvine in a hushed tone.

‘Let’s hope we find nothing worse,’ said Fry.

They moved steadily through the rooms and were joined by two uniformed officers. The beams of their torches illuminated the darkest corners, alighting on old filing cabinets and mysterious heaps of abandoned equipment.

‘Ben?’ Fry called.

She moved ahead, passing through a doorway, then another, following some instinct she couldn’t explain. She knew Cooper was here, because his car was parked nearby. But she didn’t know who else was.

Ben Cooper hardly knew what happened next. He and Geoff Naden were staring into each other’s eyes. He was aware of Naden’s left hand reaching out to grasp his shoulder, and Naden’s right hand coming up with a length of steel pipe he must have picked up from the floor.

Cooper instinctively grabbed his wrist. He wasn’t as heavy as Naden. He could feel the difference as soon as they made physical contact. He didn’t want either of them to go over that rail. But he was also conscious of Poppy Mellor immediately behind him. Cooper needed to turn round to see what she was doing, but he was reluctant to take his eyes off the other man. He felt for his extendable baton, concealed in a pocket of his coat.

‘Be sensible, Mr Naden,’ he said. ‘This won’t help anyone. It will only make things worse for you.’

‘It doesn’t matter to me any more,’ said Naden grimly.

And then there was a chaos of people shouting and lights swinging across the ceiling, picking up the figures on the walkway, then passing on and reflecting off the skylights, flashing like the starbursts in the sky over Hartington. Cooper heard his own name called, boots clanging on the metal steps.

In an explosion of light he saw Naden raising the length of pipe. Then an impact from behind threw him off balance and he dropped his baton as he threw out a hand to clutch at the rail and save himself from falling.

He dropped to his knees with the breath knocked out of him, expecting a blow to fall at any second. He heard Naden cry out – one loud, angry yell that turned into a scream of fear. Then a sickening impact thudded through the empty shed.

Cooper raised his head. He saw Diane Fry standing at the top of the steps, white-faced and ghostly behind the light of her torch. And Geoff Naden had gone.

42

43

It was so difficult to know what to talk about in the car with Diane Fry. She had so little in the way of small talk. But Cooper knew he had to make conversation, because he was getting a lift, was on the receiving end of a favour. So he asked her about the outcome of her interviews with Jason Shaw.

‘For some reason Shaw became more extreme in his intentions after Sandra Blair’s death,’ said Fry, when she’d outlined the results.

‘Well, don’t you think he was in love with her?’ said Cooper.

Fry looked at him. ‘That’s what he said. I didn’t believe it.’

‘Why not?’

‘Well, he’s not that sort of person.’

‘Are you kidding? Anybody is capable of love, no matter what else they do in their lives. Yes, even people who commit murder can be in love. You understand that, don’t you, Diane?’

She didn’t answer directly, but gripped the steering wheel a bit tighter. ‘That still doesn’t explain his reaction,’ she said.

‘It was jealousy, I think,’ said Cooper.

‘Who of?’

‘Poppy Mellor perhaps. Oh, not in that way. But Sandra and Poppy were enjoying themselves too much. It was as simple as that. Jason didn’t see it as fun. With Sandra gone, he only had two options – to give up or take it to the extreme. And he wasn’t a man who would just give up.’

Fry looked as though she were struggling to understand the emotional complexities of ordinary human beings. She concentrated on the traffic as they headed out of the town centre and over the bridge towards Welbeck Street.

‘I dare say you’re right,’ she said in the end.

‘So in a way, you see,’ continued Cooper, ‘the earl paid the price for Sandra Blair’s death, not for his development plans at Bowden, or even for the quarry scheme. He became the target for one individual’s thwarted passion, an unfocused rage.’

He watched Fry trying to digest the interpretation. He knew it wouldn’t fit with any of her logical constructs. In fact, in Diane Fry’s world, motive could be pretty much dispensed with, once you’d collected enough evidence to prove your case. Guilt was important in the criminal justice system, not reasons. The system represented by Fry didn’t want to know why people did things. It was much too hard to understand, impossible to write down on a report form. It was too human.

Cooper wished he could tell her that one day, when he thought she would understand.

They turned into Welbeck Street and Fry drew up outside his flat.

‘That was a big help,’ he said. ‘Thanks a lot, Diane.’

Fry waited while he got out of the Audi. Cooper turned and stood on the pavement, expecting her to accelerate away. He was planning to give her a little parting wave as she disappeared from his life round the corner of the street. But she didn’t do that. And his instinct for politeness kicked in again.