Daniel had never been made to do heavy drill. 'Worse than basic training?'

'Way worse,' Leon said.

Zara stood up and signalled Briggs to do the same. Then glanced at her watch.

'Quit CHERUB, or two months' punishment. I'll give you ten minutes to make up your mind.'

Zara and Briggs headed out. The twins jolted as Briggs locked them in with a metallic clank. As the boys looked at one another, Daniel eyed a picture of Nigel Kinney on the desk.

'We always knew there was a good chance we'd get caught,' Daniel said sadly. 'Maybe it wouldn't be so bad, just being an ordinary kid.'

Leon nodded. 'There are so many hot girls at that Catholic school down the road.'

Daniel looked up at one of the cameras. 'They can probably hear what we're saying.'

'But on the other hand,' Leon said, as he flicked his cheek anxiously. 'We've got the whole rest of our lives to be ordinary.'

4. MAGGOTS.

CHERUB campus was Sunday-morning quiet as a blonde twenty-two-year-old stepped up to a set of doors, dressed in tight-fitting cords and tatty Converse. She leaned forward, staring into a black square with a green light flashing above it. After a moment, a screen beneath the panel lit up with Lauren Adams, access granted.

The snaking mission control building on CHERUB campus had recently undergone refurbishment, with new floorboards and modern art. The heart of the building was a small control room aglow with computer screens. From here, the sixty or so CHERUB agents and their adult controllers who are on a mission at any given time can call in an emergency, request backup, equipment or a link to specialists whose skills range from hacking an encrypted file to making sure that a traffic light turns red when it needs to. Branching off were three smaller control rooms, which were manned during the critical phases of CHERUB's individual missions.

After pa.s.sing through, Lauren entered a broad corridor, with securely locked offices on one side and full-height gla.s.s overlooking forest on the other. Halfway along, a boy and a girl looked nervous in their grey CHERUB shirts, yet to hit their teens and about to get briefed on their first mission.

The last office had a sign Lauren found slightly ludicrous: James Adams Mission Controller.

Before Lauren could knock, a stocky seventeen-year-old in a black CHERUB shirt opened the door and almost crashed into her with an armful of papers. After an exchange of sorries, Lauren stepped into a plush corner office, with bookshelves, trendy walnut desk and a pair of leather sofas either side of a coffee table.

The view, down a gentle slope over golden trees, was spectacular. Unfortunately, James Adams let down the ambience, dressed in gym clothes, one holed sock propped on his desk and surrounded by coffee mugs, box files and mounds of paper. He was on the phone, so he gave Lauren a thumbs-up and pointed her wordlessly towards a couch.

'John ...' James told the phone. 'She's a sixteen-year-old girl and her whole wardrobe got smoked in the fire at the end of the mission. I just told her to get what she needed ... I realise I should have set a budget, John. But how was I supposed to know she was going to go to London and spend eight hundred pounds on shoes?'

Lauren smirked as she slid a backpack down her arms, settling on the only part of the couch that wasn't covered in files. As James continued talking, the black-shirt girl came back in with a roll of thick orange bags, which Lauren knew were for stuff that had to be incinerated on campus.

'I'm Fu Ning,' the girl told Lauren quietly, as James continued on the phone. 'You must be his sister, Lauren.'

Lauren nodded. 'My brother must be a pain to work for.'

Ning smiled. 'He's cool, just disorganised.'

James was continuing his conversation with his boss. 'Birmingham?' James said. 'I know about the recruitment. I told you Thursday in the team meeting, I've got Leon and Daniel Sharma lined up for that job ... What? ... Are you serious? How can they not be available for missions? ... I need those two guys. I'll give Zara a call and try to twist her arm. If it's not too serious she might let me have them back ... Right, I'll be here until noon I guess. Speak in a bit.'

James sounded frazzled as he put down his phone.

'Working hard?' Lauren asked, as James stood and gave her a hug.

'Sunday morning,' James said, as the pair embraced. 'I should be in bed with Kerry. The hours she works, and the hours I work, we barely see each other.'

'What was that about shoes?'

'G.o.d,' James said, smacking his forehead as Ning broke out in a huge smile. 'I was on a mission, girl gets all her clothes burned. She's really upset, so I'm like don't worry, take a nice shopping trip to London and get whatever you need. I fixed up a debit card and she spent four and a half grand. Totally destroyed the mission budget. John Jones is furious.'

'You told a sixteen-year-old girl to go to London and buy whatever she wanted?' Lauren scoffed.

'She's a great kid,' James protested, as Ning and Lauren struggled to contain their laughter. 'I've never seen her wear anything other than joggers and a hoodie. I didn't expect her to do that.'

Lauren smirked. 'It's almost as if someone trained her to manipulate adults and get what she wanted.'

'Fair point,' James said, shaking his head. 'So what's up in your world? Still racing cars?'

'Team's all set up for the new season,' Lauren said. 'Rat put up some seed funding, but now we're fully funded through sponsorship, unless I crash too many cars.'

'When's your season start?'

'Still got four months.'

'Scared?'

Lauren nodded. 'It's a jump. I had a hundred and twenty horsepower in the single-seater formula. This is a saloon car, topping out at five hundred.'

'Try not to get killed,' James suggested.

Lauren grinned. 'You know me, James. I'm not the kind of person who wants to be stuck at a desk behind a mountain of paperwork.'

'Up yours!' James said, giving his sister a playful dig in the ribs.

Lauren grabbed James' arm and tripped him on to the couch, but he had to run for the phone before things could escalate.

'James Adams speaking ... You need what? Well can't you get some of the carers down at The Village to round up a bunch of kids? ... Why is this even a mission control problem? ... OK, fine, I'll do it.'

James slammed the phone down and looked so stressed that Lauren took pity and pulled a sarcastic comment.

'Five hundred and fifty boxes of mission control files in the bas.e.m.e.nt of the main building,' James explained. 'They were supposed to be moved a week ago, but it got held up by the asbestos removal team and apparently John Jones forgot. So, are you girls up for some heavy lifting?'

Barefoot, dressed only in shorts and T-shirts, Leon led his twin by a couple of paces, weighted down by a huge pack and with a stocky Aussie instructor named Capstick in his ear.

'Faster, Sharma,' Capstick roared. 'If you're not at the top of this hill in one minute, I will take you down to the bottom. I will put another ten-kilo weight in your sack and I will make you run this whole circuit again from scratch.'

Daniel's instructor was no less intimidating. 'Too slow, cupcake,' Instructor Smoke yelled, kicking him in the back of the legs and sending him sprawling before skimming her boot through a puddle and spraying his face with mud. 'On your feet, stat!'

Leon glanced back.

'Don't look at him,' Capstick roared. 'Move your b.u.t.t.'

Daniel tried to pull himself up, but he'd been drilled since sunup, with planks, push-ups and a half-hour standing with the heavy pack held high above his head. There was no strength in his arms.

'I can't,' Daniel moaned, as he noticed blood between his toes.

'What's the matter?' Instructor Smoke demanded. 'Nothing wrong with a bit of blood. What do you want, a kiss better? Get on your d.a.m.ned feet.'

Daniel tried, but his arms gave out again.

'UPPPP!' Smoke ordered, as she lost patience and yanked Daniel to his feet by the strap of his backpack. 'Now shift before I kick you down again.'

Leon had reached the top of the hill and groaned with relief as he dumped the pack on the ground before doubling up, gasping.

'On your knees, both of you,' Capstick shouted, when Daniel finally stumbled to the top of the hill. 'Hands on heads.'

The ground was muddy, so the position wasn't too hard on the knees. Both boys gasped, while Daniel was now feeling the pain in his foot. The two instructors moved right into the boys' faces and started a verbal barrage.

'You are pathetic.'

'Maggots!'

'You bring shame to the CHERUB T-shirt, maggots.'

'Wrecked on day one. Do you really think you can take sixty days of this?'

'Why put yourself through the misery? You can't beat us, maggots.'

'Quit now. Go live the easy life. Geography homework and a girl with nice long legs.'

'Are you crying, Daniel? Is that a tear in your eye?'

'No sir,' Daniel lied.

'You wanna quit, maggots?' Smoke roared.

'No ma'am,' the twins shouted.

The two instructors stepped back, smiling at one another.

'You boys stay right there on your knees,' Capstick demanded. 'Keep hands behind your heads. Don't speak, don't move.'

'We'll be back in two hours,' Smoke added. 'If you're very lucky, we might bring you some food.'

5. BOXES.

Lauren Adams got a twinge of nostalgia as she crossed leaf-strewn gra.s.s towards CHERUB campus' seven-storey main building. The dishes and aerials that had adorned the roof were gone, the outer cladding removed, leaving a concrete skeleton and a dolls-house-like view into bedrooms and offices stripped of everything that wasn't screwed to a wall.

The ground-floor canteen made her particularly sad, remembering the sense of excitement when you came out of lessons and looked forward to seeing the gang. Everyone sitting around the tables, teasing and gossiping. Food fights. Early breakfasts with Rat when she first got the sense that she was falling for him ...

'OK,' James said, as he stopped walking and turned around. Lauren was taken by the calm authority in her brother's tone. A teacher's voice. 'Listen up.'

Besides James, Lauren and Ning, a dozen teenaged CHERUB agents were in tow. They were a mix of reluctant volunteers and kids on punishment.

'I've got bad news and worse news,' James began. 'The bad news is that due to a b.a.l.l.s-up, five hundred and fifty boxes of historic mission control doc.u.ments were not shifted by the army logistics team, due to a delay in the asbestos removal work. The worse news is that the lift has been deactivated, so we've got to take all of them up four flights of stairs. Once they're up at ground level, the boxes have to be taken across campus on a truck and unloaded in the archival s.p.a.ce beneath the mission control building. So let's hope we're all feeling energetic!'

'How long's it gonna take?' a girl of about fifteen asked.

James shrugged. 'Three hours, maybe. John Jones is rounding up a second batch of volunteers to help unload at the other end. And if you're not here on deferred punishment, we'll add fifty pounds to your spending accounts as a thank you.'

The volunteers seemed happier after hearing this and there was even a muted cheer.

'The interior is a demolition zone, so you must wear hard hats and hi-visibility vests. Do not stray away from the designated route.'

A temporary barrier circled the main building, its sole access point guarded by a sergeant from the Royal Engineers Corps. Like everyone else on the demolition team, she'd been living on campus for the past six weeks, but was allowed no outside communication and had not been told where campus actually was. Her uniform would usually be topped with a green beret, but special orange ones had been issued, reminding young agents that she was not to be spoken to under any circ.u.mstances.

The sergeant counted everyone through the gate, issuing everyone with a numbered dog tag and strict orders that the necklace must be returned so that they could be counted out of the secure area. She then opened a portable cabin, and distributed yellow vests, dust masks and hard hats, while telling James where to find trolleys and other moving equipment. At the same time, a beeping truck was being reversed up to the gate and four more volunteers jumped out of the back, spurred by the prospect of making fifty quid.

Once they were all equipped, a second orange-hatted army engineer led the way inside, between yellow and black danger high explosive signs. The main doors had been removed to give work crews easy access. The usually polished floor was horribly scarred and James looked forlornly down the hallway leading to the old chairman's office, missing the wooden bench where he'd so often sat, drumming his foot as he awaited punishment.

But the most dramatic change was in the concrete columns that braced the main hallway that ran all the way to the dining-room at the back of the building. These had been drilled with dozens of three-centimetre-wide holes, into which had been dropped sticks of high explosive. Between sticks ran looms of brightly coloured wiring.

'Could this go off by accident?' a girl asked warily, as the army engineer led the way towards the stairs into the bas.e.m.e.nt. James gave a nod, indicating that the soldier was allowed to answer.

'The explosive and detonators are very stable and I'm not aware of any demolition where there has been a premature explosion. What can happen is that the demolition happens incorrectly and only some of the charges go off. So please don't touch any wiring, and if any of you should accidentally drop something or trip and touch one of the looms, please let us know so that we can test the circuit.'

James and the engineer led the group down a back staircase to the first bas.e.m.e.nt. Most furniture had been removed, but the decision had been taken to entomb some equipment in the explosion, including an ancient mainframe computer and thousands of doc.u.ment boxes that were no longer needed, but not so sensitive that they had to be incinerated.

After a stretch of floor, James found himself clattering down metal stairs, wrapped around a large cargo lift which he had never previously seen. At the bottom, the stairs continued down to a third bas.e.m.e.nt, much to the astonishment of kids who'd lived in this building for some years but had no idea about these subterranean levels.

The engineer unlocked the door into a final stretch of corridor. There were no explosives, but like most buildings built before the 1980s, the mineral asbestos was used as fireproofing. Now known to cause cancer, every sheet of asbestos had to be removed so that its toxic dust didn't form part of the cloud when the building detonated. This hallway had been the last to be cleared, and the plaster and ceiling had been stripped back to bare concrete, with some dangerous-looking 1970s electrical wiring on show.

James felt intimidated when he stepped into a room which he realised sat directly beneath the campus dining-hall. There were two dozen rows of metal shelving, each stretching more than thirty metres. Everything had been cleared out, apart from the five hundred and fifty dusty box files, each one recently stickered with Mission Control do not destroy.

Made from heavy card, each box was more than a metre deep, and James quickly realised that it would take two people to lift each one upstairs.

'OK,' James said, as his sister and several kids groaned at the magnitude of the task ahead. 'It looks like we've got our work cut out.'

Four hours later, James had backache and pit stains the size of dinner plates. The fourth and final truckload of boxes had been shifted and the last batch of exhausted kids were clattering upstairs with the metal trolleys.