'Don't come down so hard on yourself, Frank,' the senior officer had replied. 'You're the one as caught him. Brought him in. Saved your lass's life.'

Elder had been polite but firm. Retirement suited him fine.

'You'll go crazy down there, Frank. End up topping yourself, like as not.'

Elder had thanked him for the thought and set down the phone.

The day had begun with a faint mist across the hills and then a soft rain that scarcely seemed to dampen the ground. By noon it was bright and clear, with only a scattering of off-white clouds strung out across the sky to the west. Elder stuffed his book down into one pocket of his waterproof coat, an apple and a wedge of cheese into the other, and set out towards the coast path at River Cove, just short of Towednack Head. For thirty minutes or so he sat on a boulder opposite Seal Island, eating his bit of lunch and alternately reading or gazing out at the water tumbling up, then falling back. Usually there were seals, stretched out on the rocks or swimming near the shore, rounded heads fast disappearing as they dived for fish, but not today.

Walking back he noticed the bracken facing up the moor had turned an almost uniform rusted brown, patched through here and there with yellow-flowering gorse. Late autumn and the nights drawing ever closer in.

He had only time to pull off his coat and unlace his boots before the phone startled him.

'Hello?'

'Frank?'

'Yes.'

'It's Joanne.'

He knew: you didn't live with someone for twenty years without recognising each turn and intonation of her voice, even the breath drawn before speaking, the weight of a pause.

'What's wrong?' Elder said.

'Does it have to be something wrong?'

'Probably.'

The breath there, head turning aside. A glass of wine? A cigarette?

'It's Katherine,' Joanne said.

Of course it was. The adrenalin had started to pulse in his veins. 'What about her?' he said.

'It's difficult.'

'Just tell me.'

Another pause. Longer.

'I'm worried. Worried about her. The way she's been behaving lately.'

'Behaving? How? What do you mean?'

'Oh, staying out late, getting drunk. Not coming home till three or four in the morning. Not coming home at all.'

'You've spoken to her?'

'Frank, she's seventeen…'

'I know how old she is.'

'I say anything, she tells me to mind my own business.'

'And Martyn?'

'Martyn's got nothing to do with this.'

Elder sighed. 'She won't talk to me, you know that.'

'She's your daughter, Frank.'

As if he'd forgotten.

'When she stays out,' Elder said, 'd'you know where?'

'She's seeing someone, I know that. I think sometimes she stays there.'

'You think?'

'Frank, I just don't know.'

He sighed again. 'All right, I'll come up. Tomorrow. The day after. I'll get the train.'

'Thank you, Frank.'

She's your daughter.

He set down the receiver, walked to the window and stared out. Mist plaiting itself between blackened filaments of hedge. The coming dark. Images of what Adam Keach had done to Katherine kept forcing themselves under the edges of his mind and he struggled to will them away.

When she had been seven, possibly eight, one of the last times she let him walk her all the way to school, right up to the gates – London it would have been, Shepherd's Bush, green school cardigan, grey pleated skirt, green tights, black shoes he'd shined the night before, book bag in her hand – he'd ducked his head towards her and she'd thrown up an arm – 'Don't kiss me now!' – and run towards her friends. Shutting him out.

Not coming home till three or four in the morning. Not coming home at all.

Seventeen.

Stupid, he felt, standing there. Stupid, helpless and old.

The bottle of Jameson's was in the drawer.

It wouldn't help, he knew that, but what else was he supposed to do?

5

The official inquiry into the shootings of William Grant and Paul Draper was opened within two weeks of the incidents taking place. The Police Complaints Authority, which routinely managed such matters, asked Detective Superintendent Trevor Ashley from the Hertfordshire Force to conduct the investigation, and as his number two, Ashley chose a newly promoted chief inspector, Linda Mills. Chalk and cheese. Ashley wore muted tweed jackets with leather patches on the arms and affected a voice that was slower and more up-country than his home, less than forty minutes' drive north from London, warranted. Mills had the lean and driven look of someone who began the day with a bracing shower and an energetic fifteen or twenty lengths in the pool.

Assisted by three other officers and two civilian clerks, Ashley and Mills were allocated a Portakabin in the car park as their base, together with a pair of interview rooms in the main building. One of the first officers called in for questioning was Maddy herself.

Taking his time, the superintendent took her through her written deposition, step by step, stage by stage, Mills watching her closely, not aggressively, occasionally making a neatly written note. Maddy wearing the same blue suit: weddings, interviews and funerals.

'Since making this statement…' Ashley said. 'When was it? The morning after the incident? You've had no further thoughts? There's nothing you'd like to add?'

'No, sir. I don't think so.'

'Sometimes, you know, on reflection…'

'Thank you, sir, but no.'

'Good, good.' With a glance towards his number two, Ashley settled back in his chair.

Linda Mills took her time. 'PC Draper and yourself, if I understand rightly, you were among the first officers to arrive at the entrance to Grant's flat?'

'Yes, ma'am.'

'And this was by design?'

'I'm sorry, I…'

'Part of the plan outlined at the briefing that you and PC Draper…'

'No. Not exactly.'

'It was what, then? Accident? Chance?'

'Yes, ma'am.'

'Which?'

Maddy hesitated. 'Chance, I suppose.'

The chief inspector glanced down at the papers in front of her. 'Not entirely.'

'I'm sorry, I don't quite…'

'According to your statement it was Superintendent Mallory who ordered you to move back down the stairs.'

'Yes. Yes, that's correct.'

Mills looked at her full on. 'Why, in your estimation, did he do that?'

Maddy took her time; her head was starting to buzz. 'I think he was concerned for our safety.'

'And that was the only reason?'

'I believe he wanted us to cover any possible escape.'

'Even though you were still unarmed?'

'There were armed officers on the stairs. Everywhere.'

'With orders to fire if necessary?'

'I assume so, yes.'

'And yet, in the event, it was Superintendent Mallory who did the actual firing.'

Maddy hesitated slightly, without knowing why. 'Yes, ma'am.'

'And the reason Superintendent Mallory discharged his weapon when he did?'

'As I've said in my report -'

'The reason was?'

'In my report, it's -'

'The reason, sergeant?'

'My colleague had already been shot. Grant had shot him.'

'And the superintendent knew this?'

'I assume so, yes.'

Mills sighed and sat back. Though it wasn't especially hot in the room, a slick line of sweat was making its way slowly down Maddy's back. Her hands were sticking to the sides of the chair. Superintendent Ashley slid one of the papers round at an angle. 'According to this diagram, the weapon Grant had used to shoot DC Draper was out of his reach here when Superintendent Mallory entered the room.'

'Yes. That's right. But he had another weapon.'

'Grant was carrying a second gun.'