"Ring Sycamore," Misty said when Ash got back to the hut. "He's pissed at you."

Ash went out to the Land Cruiser and made the call.

"Hello Ash, nice time with your girlfriend?" Sycamore asked bitterly.

"What did I do?" Ash asked.

"Your headmistress blew her stack over your antics in the canteen. She rang one of your supposed old schools; luckily she got the number from the fake file and the call went through to CHERUB, but if she'd got the school's real number and they told her they'd never heard of you it would have made a right mess."

"Is the headmistress really mad?" Ash asked.

"I called her back pretending to be one of your old teachers and I think I smoothed things over. I said you were mischievous but basically harmless."

"You said I was allowed to get suspended."

"Yes," Sycamore said. "But I didn't expect you to dunk a kid's head in a vat of baked beans. He's apparently got a nasty burn on his nose."

"Sorry," Ash said, trying not to laugh.

"Sorry solves nothing," Sycamore shouted. "What time did you get back to Fort Harmony?"

"Just now. About half seven."

"Have you seen Clark and Sebastian today?"

"No."

"Why not?"

"You know why, I was with Joanna."

"The mission is about Sebastian and Clark, not your little girlfriend. I've told Cathy to ground you for getting suspended from school. You can't leave Fort Harmony for a week."

"But what about Joanna?" Ash asked.

"Tough," Sycamore said. "Focus on your mission. You mess up like this again and I'll have you back at CHERUB scrubbing toilets on your hands and knees."

"I've got to see Joanna, please," Ash begged.

"Don't wind me up, Ash, I'm in no mood. There's two things for you to keep an eye out for. In your photos of Bungle's shack there's a white folder with a RKM logo on the side. It's on the bottom of the bookshelf under the window. Try and get a look at it. It looks like a computer manual, but Bungle doesn't have a computer. It might give us a clue what they're up to. Second, look out for a red van. Amy spotted Fire and World getting out of it, but couldn't get the whole number plate. Got all that?"

"Yes, Augustine," Ash said miserably.

"Start using your brain, Ash." Ash heard the line go dead. He punched the dashboard, ran back to his bed and yelled into his pillow.

"What happened?" Misty asked.

"Piss off," Ash said.

"It can't be so bad, Benny. You got out of school."

"He said I can't go down to the village and see Joanna."

"You know we'll only be here for a few weeks," Misty said. "I wouldn't get too fond of her."

Ash got off his bed, put his boots on and walked out into the dark.

He lay in the long grass down the bottom of the hill and didn't care that his clothes got soaked. He thought about sneaking down to the village to see Joanna, but he wasn't brave enough to mess with Sycamore. If Sycamore sent him back to campus in disgrace he'd never get another decent mission.

Ash wanted to go back to the hut, but Misty would be there with a lecture waiting. He thought about finding Sebastian and Clark, but he didn't want to spend all night shooting the local wildlife. So he stayed where he was, sulking.

Ash heard an animal or something running through the grass around him. He looked up and saw it was two radio-controlled cars. Electric ones. The only noise was rustling as they brushed the grass. He spotted the chromed radio control aerials reflecting moonlight. World and Scargill had them. After a couple of quick circuits they picked the cars up, pulled up their sweatshirt hoods and jogged away.

Ash decided it was too risky to follow. He crawled through the mud towards where Scargill and World had been standing and almost fell into a hole. It was one of the old tunnels. Ash grabbed his mobile and called Misty.

"Where are you?" Misty asked.

"Down near the road, something weird is going on." Ash explained everything. "The tunnel has a door with a padlock on it," he said. "I don't have my lock gun."

"I'll be five minutes," Misty said. "Do nothing. If they come back, say you were just exploring."

Misty ran down to Ash, keeping herself low to the ground. She shone a torch into the hole and quickly shut it off again.

"They could be back any minute," Misty said.  "You any good with the lock gun?"

"OK," Ash said.

"Got your camera?"

"Yes."

"Go have a look," Misty said. "Take as many pictures as you can and get out fast."

"Will you keep look-out?" Ash asked.

"No. If they catch you, say the lock was left off and you just walked inside. Me sitting out here looks suspicious. I'll keep back unless something starts getting heavy."

Ash took Misty's torch and lock gun and dropped into the hole. There was a deep puddle in the bottom. The padlock was easy. Inside was three metres of wood-lined tunnel with a low room at the end. Ash crawled down and started taking pictures. There wasn't much to see. Shelves of radio-controlled cars and spares, and a workbench with an orange plastic tub underneath. Ash opened every drawer and took pictures inside.

Ash turned to leave, half-convinced someone would be behind him. Nobody was. He scrambled back down the tunnel, shut the padlock and ran uphill to Misty.

"Sweet." Misty said. "See anything?"

"Toy cars and junk. Hard to see with the torch."

"The flash on the camera will pick up more than you saw in the dark," Misty said. "Maybe something will turn up on the photos."

"There must be stuff worth hiding in there," Ash said. "Otherwise they wouldn't bother keeping it secret."

"I'm gonna stick around and see if they come back," Misty said. "You go up to the hut and ring Sycamore. Arrange to meet him somewhere. He'll want to look at the pictures straight away."

After he'd met Sycamore, Ash went back to the hut and fell asleep. He got the best sleep he'd had in ages, without Misty there snoring.

Misty shook Ash awake at 2 a.m. She looked happy.

"It's all going down, Ash. Fire came to the workshop. You were nearly caught, only missed him by about three minutes. He took a big backpack of stuff out and walked off. I followed him up the hill to Green Brooke. You'll never guess what the radio-controlled cars are for."

"What?" Ash asked.

"They have a storage tray. They load them up with stuff and push them through a tiny gap in the security fence around Green Brooke. They drive the cars inside the fence and drop the cargo at the back of the conference hall. The cars are too small and fast to get detected by the security cameras and alarms."

"Couldn't they book a room and bring the stuff into the hotel?" Ash asked.

"Every guest brings luggage into Green Brooke hotel," Misty said. "But the conference hall is under police guard until Petrocon starts. Everyone gets searched on the way in. There's X-ray machines. All your bags get turned out, they pat you down and go in your pockets."

"So," Ash said. "They're smuggling a bomb into the conference hall, bit by bit, on the back of radio-controlled cars. There must be someone working on the inside screwing all the pieces together."

"Must be. I spoke to Sycamore. They're sending people down to look at the stuff the cars dropped, but they won't take it away. They want to see who comes and picks it up."

Ash laughed. "They're gonna lock those guys up and throw away the key."

"Poor Scargill," Misty said.

"You don't actually like that freak, do you?" Ash asked.

Misty shrugged. "I feel sorry for him. He's just a lonely kid trying to impress his big brothers. The tough guys in prison will eat him for breakfast."

"You do like him," Ash laughed. "He's the world's biggest nerd."

"You're such a twelve-year-old sometimes, Ash," Misty said. "You've never even had a conversation with Scargill. There's more to a guy than looking good and having big muscles."

"Marry him and get it over with," Ash said. "So what happens next?"

"Nothing changes. We keep our ears to the ground and see what comes up. Sycamore wants you to concentrate on Bungle and Eleanor. We know they're involved, but there's still no proof."