You weren't supposed to wear CHERUB uniform off campus for security reasons, but Ash wore his grey shirt all the way home hidden under his tracksuit. He woke up on the plane and peeked down his chest to make sure it wasn't a dream. Serena was asleep in the next seat. Ash could see the grey tail of her CHERUB shirt hanging out the back of her jeans. He put his arm around her and pulled her head onto his arm, stroking her hair as she gently snored next to him.

Everyone was in a good mood. Even the instructors, who got a three-week holiday before the next batch started training. Serena stopped acting tough and surprised Ash by turning into a normal eleven-year-old girl. She told Ash she couldn't wait until her nails grew back and her skin was flawless once more. She even bought a pen and card in the airport gift shop and got everyone to sign it for the instructors. Ash told her he thought it was dumb. He remembered that Surge had been happy to get them thrown off the course to win a bet. It might be Lt Surge's job to make trainees suffer, but he seemed to enjoy it as well.

The van from the airport left them at the training building. The new operatives picked a few things up from their lockers and changed out of their casual travel clothes into uniform. Ash kept one of the filthy blue shirts with the number seven on as a memento. Serena was holding out a key.

"Help me move my stuff?" Serena asked with puppy eyes.

"Where to?" Ash asked.

"The main building. Red shirts live in the junior block." The instructors wanted them all out of the training area fast so they could get home.

Drew was waiting for his twin outside the training compound. His arm was out of the sling. Ash felt sorry for Drew. having to start training again. Ash gave him a friendly shove.

"You'll get there," Ash said. "No worries."

Brendan put his arm round his brother. Serena was running ahead, excited, "Come on, Ash."

Ash went after her to the junior block. He hadn't been there before. It was the middle of the morning so everyone was in class. Serena's room had kiddies' furniture: a plastic desk, bunk beds and a big wooden trunk with My Toys painted on the side. The wardrobe had a green teddy on the doors.

"What a divine room," Ash said, trying not to laugh.

"Shut your pie hole," Serena said, "and carry." She had packed everything before training started.

"You must have been confident," Ash said.

"If I failed this time, I was going to leave CHERUB. You don't have to become an agent if you don't want to."

"Where do you go if you leave?" Ash asked.

"They send you to a boarding school. In the holidays you stay with a foster family."

"You really would have left?"

"I promised myself," Serena said. "That's why I got so upset on Christmas Day when you got us in trouble."

Ash stayed quiet. He didn't want the conversation straying towards their agreement to fight in the dojo. They packed Serena's stuff on to one of the electric buggies that staff used around campus.

"Where's your new room?" Ash asked. Serena showed him the number on her key ring.

"Sixth floor," Ash said. "Same as me, we're practically neighbours."

They walked back to Serena's old room and did a final check to make sure nothing was left behind. Serena had tears streaking down her face.

"What?" Ash asked.

"This has been my room since I was seven," Serena sobbed. "I'll miss it." Ash didn't know where to look.

"Sere, the rooms in the main building are about fifty times cooler. You've got your own bathroom and computer and everything."

"I know, but still..." Serena sobbed. He put his arm around her once more and gave her a shoulder to cry on.

"Give over," Ash whispered on her ear. "Can I drive the buggy, I've never done it before?"

The buggy was overloaded with Serena's stuff and felt like it might tip over on a bump. The bell had gone for a lesson change. Kids were going between the buildings. A few of Serena's friends stopped the buggy and congratulated them on passing basic. Misty burst out of a door.

"Hey," she shouted. Ash hit the brake.

"Congratulations," Misty said, leaning into the buggy and hugging both of them.

"You taught Ash to swim, didn't you, Misty?" Serena asked.

"Yes," Misty said.

"What's with all this?" Serena asked, flapping her arms about in a wobbly front crawl.

"I don't swim like that," Ash said peevishly. Misty and Serena both laughed.

"I only had three weeks to teach him," Misty said. "He's getting more lessons." Misty copied Serena's impression of Ash's swimming and they both laughed even harder. Ash would happily have thumped them, only they could both easily batter him.

"Anyway, Ash," Misty said. "I've been looking for you everywhere. I've got something to show you."

"What?" Ash sulked.

"Ash, I'm sorry," Misty said. "I'm your teacher so I shouldn't laugh at you. I promise I'll cheer you up if you come with me." Ash climbed out of the buggy.

"Where to?"

"You look really fit, Ash," Misty said. Ash wasn't sure if she was saying it to make him feel better.

"Are you OK to move that stuff on your own?" Misty asked Serena.

Serena nodded. "Someone will help." Misty led Ash back towards the junior building.

"What is this?" Ash asked.

"I wasn't sure you'd make it through training first time," Misty said. "I'm impressed."

Ash smiled. "Another three or four compliments and I'll forgive you for what you said about my swimming."

They walked into the education block in the Junior building. It looked like any ordinary primary school, with little kids' paintings on the walls and plasticine models on the window ledges. Misty stopped by a classroom door.

"There," Misty said.

"What is this?" Ash said. "Can't you just tell me?"

Misty pointed at the door. "Have a look." Ash stuck his face up to the glass. Inside, ten kids sat on the floor chanting phrases in German. The red shirts wore the same uniform as everyone else, only with trainers instead of boots.

"See it?" Misty asked.

"No," he said impatiently. "I don't even know what I'm looking for." Then it hit Ash like a bomb.

"Shit," he said, grinning. He knocked on the classroom door and walked in.

"Shit," Ash said again, loudly, in front of the teacher and all the kids.

The German teacher looked furious. "My sister," Ash said.

He couldn't think of anything else to say and stood with his mouth open.

"Excuse our interruption, Miss," Misty said calmly. "This is Leaf's brother, Ash. He's just finished basic training and was wondering if you could excuse her."

The teacher flicked his hand at Leaf. "Go on, just this once."

Leaf scrambled up from the carpet and jumped into Ash's arms. She was heavy. Ash stumbled back a couple of paces before he got his balance.

"Hallo mein grosser Bruder," Leaf said, grinning.

"What?" Ash asked.

"It's German," Leaf said. 'It means hello, big brother.'

Misty had a lesson to go to. Leaf walked Ash to her room.

"I can't believe this," Ash said, grinning uncontrollably.

The best he'd hoped for was being able to see Leaf a couple of times a month. Having her walking along in front of him in a CHERUB uniform was too much to take in.

Leaf's room was like Serena's old one, except everything was newer.

"Can't believe this," Ash said again, slumping on to a beanbag. "I just cannot believe this."

Leaf laughed. "So you're pleased to see me?" She got Cokes out of her fridge and threw one at Ash.

"I mean how... I mean..." Ash giggled. "Why are you here?"

"Because Giovanni punched me in the face," Leaf said.

"He did what?" Ash said, shocked.

"Punched me. I had massive black eyes."

"That arsehole," Ash shouted, kicking out at the wall. "They never should have let him look after you. I knew something like that would happen."

Leaf squeezed up next to Ash on the beanbag.

"I hate Gio's guts," Leaf said. "Mrs Reed asked what happened to my eyes when I went to school the next day."

"You told her the truth?" Ash asked.

"Yeah. She got the police. They saw all the smuggled cigarettes when they went round to arrest him; so they busted him for that as well."

Ash laughed. "Serves him right."

"I got taken to Coumarine House," Leaf said. "Nobody could find where you'd gone. I got really upset. I thought I was never gonna see you again."

"So how long did it take them to find me?" Ash asked.

"I was at Coumarine House three days. Fourth day I woke up here."

Ash laughed. "Freaks you out, doesn't it?"

"They wouldn't let me speak to you. Oak took me to see you though. I watched you and that blonde girl doing Karate. She was killing you. It was so funny."

"Did you have to do the tests to get in?"

"No," Leaf said. "They're only if you're older and you're going straight into training."

"That's so jammy," Ash said. "The tests half killed me."

Leaf whacked him across the arm. "Leave my hair alone." Ash was winding it around his fingertips. She hated him doing that.

"Sorry," he said. "Never even realised I was doing it."

"I'm on a special programme," Leaf said. "Loads of running, swimming, Karate and stuff, so I'm really fit when I start basic training."

"You're ten this year, aren't you?" Ash said.

Leaf nodded. "September. I'm trying not to think about basic training."

"But you think it's cool here, don't you?" Ash asked. "You're happy?"

"It's superb," Leaf said. "There's always loads to do. Did I tell you, they took us skiing? I got this bruise on my arse the size of a CD."

Ash laughed. "I can't imagine you on skis."

"And you want the best news?"

"What?"

"They found drugs and tons of stolen stuff in Giovanni's flat. Guess how long they put him in prison for?"

Ash shrugged. "Five years?" Leaf pointed a finger at the ceiling.

Ash grinned. "Seven years?"

"Eleven and a half years!" Leaf said. Ash punched the air.