She watched, holding her breath, as he put in the earring. From school to cool.

A hundred yards or so from the entrance, Farrell eased away from his schoolmates and joined up with two new boys who were crossing the road fast towards him. These boys wore uniforms of their own: Nike caps; New Balance trainers; Kappa casuals. They moved like men but looked young enough to make Kitson question why they weren’t in school themselves.

The three hailed each other, though it was impossible to make out the words being shouted. Fists were clenched and proffered. Kitson was reaching for the door handle as the knuckles kissed in greeting and the trio moved off together towards the shops.

‘We on the move?’ Stone asked.

Kitson opened the door. Stepped out, buzzing as she thought about Adrian Farrell’s interesting new mates. His nice, white friends.

‘Let’s get some air,’ she said.

Porter came through on the radio. She suggested to Thorne that they should meet somewhere between their two vehicles. Put their heads together.

They walked up Fairfield Road, crossing over the Docklands Light Railway towards Old Ford. ‘Barry Hignett came down about half an hour ago,’ Porter said. ‘He was keen to get cracking.’

‘Like the rest of us aren’t?’

‘I mean really on the hurry-up. So we sent a couple of the lads in to see if there might be any help around. See if we can get a bit closer.’

They stopped to let a lorry back out of a goods yard. The driver scraped a wall, pulled forward a yard or two and tried again. This time, they walked around, ignoring the exhaust fumes and the beeping of the reversing alarm.

‘Thanks for telling me.’ Thorne’s tone made it clear that he wasn’t the slightest bit grateful; that, in his opinion, he should have been told half an hour earlier.

‘I’m telling you now, so there’s no point getting snotty.’

‘Hignett getting shit from your detective super, you reckon?’

‘For definite,’ Porter said. ‘And I wouldn’t be surprised if Tony Mullen had been on at him, too. Poor sod’s got it coming from everywhere.’

‘Is he still here?’

‘Gone back to base.’

‘Makes sense,’ Thorne said. Which it did. As SIO, Barry Hignett would need to stay close to Central 3000. From there, he could monitor all events, could communicate with every member of his team, while staying within easy reach of the top brass. There was a buck in this case, same as in any other. It just flew around that little bit faster before it stopped.

Porter slowed outside a swanky-looking development of flats. A map on the gate showed the location of the swimming pool, the sauna, the private shops. ‘I could do with somewhere like this,’ she said. ‘My place is a shithole.’

‘This is the old Bryant & May factory,’ Thorne said, staring through the gates. ‘Where the matchgirls’ strike was.’

Porter shook her head.

‘End of the nineteenth century.’ He pointed towards the building. ‘The girls in there went on strike for better pay and conditions. Turned into a national story. Kicked off the trade union movement, more or less.’

‘Lit a match under it.’

Thorne was already thinking ahead and missed the joke. He turned around, pointed back towards the Bow Road like a tourist guide. ‘You’ve got Sylvia Pankhurst’s original campaign headquarters over there. Votes for Women and all that.’ He tried to keep a straight face, but couldn’t resist the crack. ‘And now look where we are.’

‘You asking for a slap?’ Porter leaned into him as she stepped past and kept walking.

‘So where’s this flat of yours?’

Her mobile had barely begun to ring when Porter snatched at it. Thorne knew that the phone had a ringtone he would probably recognise, but he’d never heard enough of it to place the tune.

When the call had finished, they started back towards Conrad Allen’s flat. ‘Sounds like you got that help you were looking for,’ Thorne said.

‘We’ve got an old girl in the flat next door who’s a major fan of ours. She got her front door kicked in a couple of weeks ago, and apparently the uniforms were extremely helpful. One of the tech boys is up there now setting some gear up.’

‘Reckon they’re in there?’ Thorne asked.

Porter’s look made it plain she hadn’t the slightest idea. ‘There’s been fuck-all to see, so it’s glass-against-the-wall time.’

They didn’t say a great deal else after that. They just picked their feet up, jogged back around the lorry that was still trying to back out.

Andy Stone got the formalities out of the way. Made the introductions, waved the warrant cards around.

It was a very pleasant smile. Kitson wondered how much more of it she might be seeing in the days to come. ‘We’ve already done this,’ Adrian Farrell said. ‘We spoke to a couple of officers yesterday after school.’

Kitson took a step closer, flashing a pretty decent smile of her own. ‘It’s not about Luke Mullen,’ she said. ‘We’re investigating another matter.’

They were gathered outside a bakery and sandwich bar in a small, pedestrianised precinct off the Broadway. The place was busy, with workers from local shops and offices zigzagging between pushchairs to grab lunch or do a quick bit of shopping. Farrell and his two friends leaned against the window, eating sausage rolls from paper bags. They’d stopped talking, elbowed each other and stared as Kitson and Stone had walked up the gentle slope of a long wheelchair ramp towards them.

One of the boys in the baseball caps nudged his companion, nodding towards Farrell. ‘They’ve finally come to get you, guy.’

‘Yeah, the cops is well on to you for sure.’ His friend spluttered the words through a mouthful of hot food and started to laugh.

Farrell grimaced at the pair of them. ‘Shut it.’ Then, back to Kitson: ‘Sorry about them. Bloody rabble.’

‘A student was murdered a couple of miles from here,’ Kitson said. ‘Last October, in Edgware, you probably saw it on the news.’ Farrell’s expression scrunched up, like maybe he thought he had. ‘Ring a bell?’ Kitson watched his eyes drop for half a second to her tits, then back up again. ‘His name was Amin Latif.’

Farrell certainly looked as though the name meant nothing to him.

‘You don’t remember it? I’m quite surprised.’

‘I remember our chaplain leading a special prayer in assembly. Right before the hymn. He does that, you know, for disaster victims, stuff like that. Yes, there was definitely one for some poor bugger who’d been murdered. It would probably have been around that time.’

There was loud music coming from the record shop opposite. Something cheery and pointless.

‘So?’

‘So what?’

Kitson tried hard to meet his eyes. ‘Did you say a prayer for Amin Latif?’

Farrell sniffed and looked away from her, stepping aside as a group of teenage girls came out of the bakery. One of his friends made a comment under his breath. A girl told him to piss off.

‘Should you be talking to me?’ Farrell asked.

‘Sorry?’

‘Without the presence of any legal representation. Without my parents.’

There was an impressed whistle from beneath one of the baseball caps.

‘It’s just an informal chat, Adrian.’

For the first time the boy looked slightly alarmed, though only for a second or two. ‘How d’you know my name?’

‘The police know everything,’ one of his friends said.

The other pointed at Farrell, mock-serious. ‘They know when you last had a wank, guy.’

Andy Stone stepped forward, corralled the designer-clad double act into an adjacent doorway. ‘Why don’t I get your names? Just so we don’t feel like strangers.’

‘You’re seventeen,’ Kitson said. ‘Which makes you legally responsible.’

Farrell watched his friends, nodding his head to the rhythm of the pop song.