An old adversary and ally is called in to help the team. Can they trust him ? Who is he really working for ?

Frank rubbed his chin doubtfully and looked across at Stella. "Are you sure this is a good idea ?" he asked. "We've got no idea if he's on the level. This guy is seriously dangerous. What if he's working with KORPS ?" he asked.

"There's no way he's ever going back to KORPS after what they did to him !" said Stella.

"That's not what you said when we had to break him out of prison," Frank reminded her.

"Yes, I know. Well, he proved himself there didn't he ?" asked Stella.

"He did, briefly at least. The thing is Stella, you're expecting me to put the safety of my team into the hands of this, frankly, rather deranged and deadly individual," complained Frank. "Is it worth the risk ?" he asked.

"Do we have a choice ?" asked Stella.

Frank sat back in his chair and rubbed his hand over his hair. "I'll call them down," he said finally, reaching for the communicator.

Aneisha was sitting in geography wishing it would all end. Mr. Flatley had decided that a good way of remembering information about the different countries they were studying was to learn a song from the region in the local language. He was now attempting to teach the class some Italian. It wasn't going well. "No, not Valerie, Roly, it's Volare," said Mr. Flatley.

"Didn't Amy Winehouse do that one Sir ?" asked Roly, looking completely confused.

"No, I don't think she was alive," said Mr. Flatley, sighing. "Now, listen carefully to the lyric everyone !" he encouraged them.

Aneisha glanced across and noticed that as usual, Zoe was listening and joining in as best she could. Dan was merely staring into the distance. His eyes were wide open with that 'Yeah, I'm really paying attention' look which always meant he was dreaming about something. Aneisha's guess was that he was either dreaming about Zoe or spying. On balance, she guessed it was probably spying. He looked a lot dreamier when he was thinking about Zoe.

She checked out Tom who was looking alertly at his text book. No, he wasn't. Tom was looking alertly at his tablet computer which he had balanced inside his propped-up text book, to hide it from the teacher's view. Aneisha smiled to herself. This team really had turned not paying attention into a fine art. It was a huge relief when she noticed her pencil flashing. She glanced around at the others. They'd all noticed except Dan who was still staring the thousand yard stare. When Mr. Flatley walked to the back of the class to try to get Byron to pick out the chords on his guitar, Aneisha, Tom and Zoe all stood to leave. Tom pulled on Dan's sleeve as he went past, causing him to stand up and follow. Suddenly realising what he was doing, Dan ducked back to grab his bag, book and jacket before following the others quietly out of the room.

The team ran as quietly as they could through the school corridors to the janitor's cupboard. After being transformed into their spy outfits they stepped out of the lift. Aneisha glanced across at Dan. "You could really do with one of those things at your house," she said.

"What do you mean," asked Dan sounding annoyed. "I'm under cover aren't I ?" he asked.

"Boy, it's a good cover !" said Tom. "Anyone would think you were just a typical untidy school kid," he added. Dan looked as if were about to argue when his expression changed to one of shock. The others looked at him strangely and then turned to see what he was looking at. They stiffened in surprise at what they saw.

Standing between Frank and Stella was a much cleaner, tidier, better dressed Shadow Master. He looked completely different to how they had first met him when they broke him out of his secret top-security prison. His hair had been cut into a neat style. His was wearing dark clothes and shoes. Never-the-less, he was clearly the same man. The suspicious, angry eyes were the same. He stared at them expressionlessly and smiled slightly at their shock.

"You look surprised to see me," he said, evenly.

"Well, yeah. We kind of assumed we'd never see you again !" said Dan. "Wouldn't exactly call you matey, if you know what I mean," he added.

"That would be a fair assessment," agreed the Shadow Master coolly. "However, we now share a common enemy and there is a pressing matter which must be dealt with," he said, turning towards Stella.

"Yes," she said, sounding slightly nervous. "We have a mission for you, and it will involve working with the Shadow Master."

All four teens stared at her. "Us," said Tom pointing at his chest, "with him ?" he said, pointing at the Shadow Master.

Frank cleared his throat. "Well, this mission isn't without its issues," he said. "However, on balance, I don't think we have much choice. Perhaps you can explain," he said to the Shadow Master.

"As you know, I was formerly a member of KORPS," began the Shadow Master. "I have been dedicating myself recently to bringing them down, especially the Mastermind and the Crime Minister. Those worms betrayed me, and they shall pay !" he snarled. He cleared his throat and began again, in an expressionless voice. "As part of my investigations I came across a conspiracy to murder key world figures, using secret KORPS agents."

"Aren't all their agents secret ?" asked Aneisha.

"Of course," agreed the Shadow Master, with a small bow towards Aneisha. "However, there is something different about these agents."

"What ?" asked Tom.

"I don't know. That is what worries me," said the Shadow Master.

"I can understand your scepticism," said Stella in the silence that followed the Shadow Master's odd final statement. "The Shadow Master informed us earlier this month of an intended victim of this conspiracy. We ignored him, and the target was assassinated in very peculiar circumstances," she added, frowning.

"Who killed them ?" asked Dan.

"We have no idea," said Stella.

"How were they killed ?" asked Tom.

"We don't know that either," said Stella. "The issue here is, that the Shadow Master has information that he won't give us unless he becomes part of our team," she explained. "He specifically asked to work with you four."

"What ? Why us ?" asked Zoe, speaking for the first time.

"Because I know I can trust you," said the Shadow Master.

"How do you know he didn't kill them ?" asked Dan, sceptically. The Shadow Master looked at him with an appreciative smile.

"As it happens, he was in a meeting with the Head of MI9 when the assassination took place," explained Stella.

"That only means he didn't do it himself," said Dan. "He could have got someone else to do it."

"I no longer have the necessary organisation at my disposal," said the Shadow Master. "Unfortunately my reputation precedes me and I am unable to recruit operatives," he explained with a thin-lipped smile.

"Nobody will touch you ?" asked Dan.

"Precisely," agreed the Shadow Master.