Brad stopped in a secluded corner of the library car park. Mick stared at the library for a few seconds, trance-like.

‘We haven’t got all day,’ Brad said.

‘Tim’s still got an overdue book out from there,’ Mick said. ‘Do libraries still have those amnesty days?’

Brad shook his head in disbelief. ‘Mick, we should—’

‘Half an hour maximum,’ Mick cut in. He kicked his door wide. ‘Any longer means I’m in handcuffs: so, get away and have a good life.’

He got out and for a moment stood and thought about how he’d failed himself when Seabury’s wife knocked off his mask. The embarrassment was so intense it gave him an instant headache. He got out, crossed a field, and climbed a fence into his backyard. He opened the door and crept into his own house like a burglar.

He checked out the front window. No strange cars. None of his colleagues’ cars. The who and why and how of the road traffic collision would still be a source of confusion, so he still had time before someone worked it out. But not much. He got changed: elastic-waisted jeans, a zip fleece and running shoes. All black, of course. Stakeout gear needed to be comfortable. His put his bomber jacket back on and got to work.

He started with the books from his bedroom cabinet. Old paperbacks from the YMCA shop where Tim volunteered. He ripped out page after page and tossed them around like confetti. The clothing was next, hauled from drawers and wardrobes and scattered everywhere.

The fluid came last. Splashed all over. He left the kitchen until last. Five feet from the back door, he grabbed a roll of kitchen towels and pulled a lighter from his pocket.

‘Brad Smithfield’s alibi for the night Rapid was killed was perfect indeed.’

Mick froze. And slowly turned.

Standing at the back door was DI Gondal.

‘He was being interviewed by police about the murder of Rocker,’ Gondal continued. ‘Just a simple follow-up interview, supposedly at his own house. But I just found out who conducted the interview. DCI Mick McDevitt. And he was all alone with Smithfield for a couple of hours, right around the time Rapid got stabbed in the brain in a stinking alleyway.’

Mick’s eyes cast left, to the worktop loaded with money boxes. Eighteen filled sweetie jars that he and Tim had filled together. Just for a moment, he wondered if money could get him out of this one, because he really didn’t want to be forced into a different action. He had ninety grand: Gondal would take two years to earn an amount like that.

‘Did you put Smithfield up to it? Killing the dealer? Did you just cover it up? Maybe in return for helping him beat the murder of Rocker? You knew that the dealer was selling Buzz, didn’t you? Was that why he had to die?’

‘Don’t say another word about that,’ Mick hissed at him.

‘Okay. Try this. I thought about what Ramirez’s mother had said. About the police going into her attic. I looked into it. Turned out she was talking about when he was suspected of stabbing a guy in Kensington five years ago. You mentioned that investigation. But you didn’t mention that you personally oversaw the search of his house.’

So, he knew. Mick felt his heartbeat increase with the realisation that he wasn’t buying passage out of this problem. And then he became aware of the lighter in his hand, and the flammable mess everywhere, and the stench of petrol that was impossible to ignore.

‘I was praying I had it wrong, so I dug deeper,’ Gondal said. ‘I learned that you’d requested a couple of PNC searches. One was this morning. Registration plate for a Suzuki motorbike registered to eighteen-year-old Darren John Crowthorne. An hour after your search, he was riding to college when he was knocked off his bike and then ran over again. Twenty-five-year-old Volkswagen Transporter, but with plates cloned from a five-year-old version of the vehicle.’

But the point of no return was still ahead, and there could still be a way out of this. Mick’s brain cycled through options. His jaw started to throb.

‘But that’s not the scary search,’ Gondal continued. ‘There was also a PNC search you requested en route to the Grafton murder scene last night. I spoke to the operator you called, and she said DCI McDevitt had spotted a couple of guys racing their vehicles along a street. Basic vehicle search. The results had come back clean. Just a pair of guys comparing dick sizes, no big deal. That’s what you said to her. But the names are a big deal. Harold Bond, who was viciously attacked in his home that same night. And Karl Seabury.’

Mick’s shoulders relaxed, and he let out a long breath. Gondal took a step forward.

‘You have to go in,’ Gondal said.

‘Why, Manzoor, why?’ Mick said, hanging his head.

‘Because you lied, Mac. You swore to fairness, integrity, diligence and impartiality. You remember that oath? That badge is a lie. Your life is a lie.’

Mick raised his head, but now laid his eyes upon the ceiling. ‘This shouldn’t have happened, Manzoor. Shouldn’t have happened.’

‘But it did, Mac. It did. You chose this path, but part of me understands why. But it ends here.’

Now Mick’s eyes dropped to his colleague. ‘No, Manzoor, you shouldn't have come here. That shouldn’t have happened. I guess I taught you too well.’

Gondal took a step forward, into the kitchen. Into Mick’s space, which calmed the waves in his mind. He knew the feeling too well: acceptance of the inevitable.

But Gondal misread it: ‘The right choice, Mac. It’s over. We’ll drive to the station together, but I’ll let you walk inside alone. No handcuffs. I’ll let you do it that way because, God knows, you’ve had enough heartache. Old wounds will be opened about—’

‘I told you not to bring that up,’ Mick said quietly.

‘I know, Mac, I know. You returned to work and it was the first thing you said. Nobody is to mention what happened. Nobody is to talk about it. We stick to talking shop. But I think we’re past that now. Is all of this because y—’

Gondal stopped as the kitchen roll flew at him. He put a hand up to deflect it, shocked by the attack. In that time, Mick had covered the five feet between them. He landed a hard headbutt, right into the nose, and Gondal dropped straight down onto his knees. Then Mick had the knife in his hand. A big guy with a knife, and an overweight man on his knees was no contest.

Mick grabbed Gondal’s hair at the back and pulled him forward, into the blade.

‘I killed that fucking cunt. For playing a part in it.’ Mick dragged Gondal deeper into the kitchen and dropped him. His colleague’s blood began to mix with the petrol on the lino. Gondal rolled onto his front, hands clutching his neck as he tried to get his knees under him.

Mick said: ‘When you get to Heaven, tell God you said the wrong thing to the wrong man, okay? He’ll roll his eyes and wonder why we never learn.’

He picked up the kitchen roll. He stepped into the back doorway.

‘By the way, Gondal, here’s something else you can take with you. I killed Grafton. There you go. You solved your final case.’

Gondal’s fading eyes registered a moment of disbelief. Then the man’s movements slowed and stopped, as if his batteries had run out.

Mick lit the kitchen roll aflame, but held it and watched Gondal until the blood pumped no more, until the ragged breathing had stopped. Only when he was sure his long-time partner was beyond the reach of more suffering did he toss the flaming roll.

But at his back fence, ready to climb, he stopped as he felt his heart lurch. He turned, wanting to go back, wanting to drag Gondal out of the burning kitchen, but it was too late. For a moment, he fought back tears, watched black smoke pour out of his doorway, and wished he’d never learned the story of a lucky twelve-year-old Danish girl.