Panic shot through Jude as she fell  …

… a few feet. She landed in a mixture of soot and dust, coughing as she crawled out of the chimney and bobbed her torch to light up the dark space. She was in a small sitting room, whose curtains were drawn. Relieved, she stood and patted herself down, the soot forming a circle around her on the thick white carpet.

There were two armchairs facing the empty fireplace that Jude had just crawled out of. It was lucky the fire hadn’t been lit. Jude had always assumed if there was a fire waiting at the bottom, she would feel the heat as she slipped down the chimney and climb out again – but she hadn’t factored in what might happen if her magic failed. They definitely needed to adjust their plan for next time.

The beam of light from her torch picked out a portrait of a frowning old woman on the opposite wall; her narrowed eyes looked as though they were locked on Jude’s. A little sideboard stood in the far corner and resting on it were various drinks in pitchers.

All in all, the room seemed perfectly ordinary, which was slightly disappointing. On their last mission, they had broken into the house of a man who loved carpets so much that everything was carpeted – the floors, the walls, the ceiling, even the siplings he had tried to make pets. They were teddy-bear-like creatures that normally made their homes in rubbish, and it had been funny to see them crawling around the house dressed in jumpers made of discarded carpet.

There was a thump behind her as Moorley crashed down, spluttering as she emerged from the chimney.

‘Note for next time: we need to eat more climbing magic,’ said Jude, stifling a grin at Moorley’s irritated face.

‘Get your robe on,’ Moorley snapped, swinging her backpack off so she could pull out two thin black robes and two masks of feathers, handing one of each to Jude and keeping the second set for herself.

Their operations were straightforward: they found crooked members of the Consortium and scared them into thinking they were magic-keepers. Magic-keepers were responsible for giving out licences to people who made tamed magic, doing spot checks to make sure the magic was safe to use, and investigating initial reports of people trading magic illegally. Usually, the government worker promised to stop dealing in illegal magic … and on rare occasions there were good pickings to be had. In their last haul, they had stolen some magic vitamins so powerful they could help a person hear through stone walls. Jude had added them to their little stock of magic, which was currently running very low – she was hoping to get some more tonight.

She knew she was supposed to be a reformed thief, but she liked to flex her skills – make sure she didn’t get rusty. Who knew – one day thieving might just save her life … Or find her cool magic that would mute the annoying kids in her class at school.

Moorley gave Jude the final part of their disguise: some basic magic that would make them appear taller than they were. It helped trick people into thinking they were adults, because obviously no one would believe twelve- and sixteen-year-olds could be magic-keepers. But with the magic came side effects of dizziness and loss of balance, because while they didn’t actually grow, it gave the sense they were looking down from a huge height.

Jude ate the liquorice-like magic and tied the mask over her eyes, concentrating on seeing from a taller viewpoint. The room spun slightly and she took a few uncertain steps.

‘Here,’ said Moorley quietly, giving Jude a second piece of magic: lifting magic, which would come in handy if Hurly didn’t cooperate. Jude slipped it into her pocket and they left the sitting room, heading into a dark corridor. There were a few flickering torches on the walls, which only half-lit the space.

From scouting missions they had done, Jude knew Hurly Robbincon would be in his evening room, having a cup of hot chocolate before bed as he did every night. Jude reluctantly let Moorley lead the way, since she was the one who’d paid fifty kira to a criminal contact for a map of the house. It had wiped out their last bit of money, but Jude hoped it would be worth it.

‘Weird that it’s so dark,’ Jude muttered. She had a sudden feeling that something was wrong.

‘He’s probably trying to save money,’ replied Moorley. Jude wasn’t sure this was right. From what they knew of Robbincon, he was a well-off judge who had started dabbling in the illegal magic trade on the side. He had no need to save money.

She forced the worry away as excitement rose in her – this was exactly what she needed to perk her up before another long day at school tomorrow. Her education before they’d come to live with the Westons had been patchy, to say the least. It wasn’t as though she had no knowledge – she knew all about the seedy underbelly of the criminal world, where to source illegal tamed magic, how to fight off deadly raw-magic monsters. But at school, that didn’t matter. On this mission – sneaking into someone’s home, breaking the law – she was in her element. Just for now she could forget about how badly she was failing at school and enjoy herself.

Moorley pushed open a door, which led to a room lit by a crackling fire. A man with grey hair sticking up in clumps on his head, dressed in red-and-white striped pyjamas, was sitting on an armchair. He was sipping his hot chocolate peacefully.

‘Ahem,’ said Jude, folding her arms. The man’s head snapped round and he leapt up, spilling hot chocolate down his front.

‘Who are you?’ he gasped, clutching his chest. ‘What do you want?’

‘We’re magic-keepers,’ said Jude smoothly, deepening her voice so it sounded gruffer and not like that of a twelve-year-old. She didn’t relish scaring people, but Robbincon had been particularly terrible in the type of illegal magic he’d been trading, magic which would freeze another person in their tracks, leaving their legs wobbly for weeks afterwards. He deserved a bit of a fright. ‘And we’re here because it has been brought to our attention that you’ve been dealing in highly illegal magic – very bad, especially since you’re an esteemed judge.’ Jude liked to get into character when she pretended to be a magic-keeper. She acted high and mighty, looking down on everyone else. The role was partially based on her Aunt Morgol, who was a stickler for rules.

‘Who sent you?’ Robbincon got to his feet. ‘The Prime Magister surely wouldn’t – was it Esmerelda? She’s always been a stick-in-the-mud. Or Mortin?’

‘We sent ourselves,’ said Moorley. ‘Magic-keepers are a separate department – we make our own decisions.’

Moorley and Jude had done careful research into magic-keepers; their identities were kept hidden, for their own protection, as they had enemies all across Farrowfell. Many people found them to be overly harsh and restrictive. It meant Robbincon wouldn’t know they were lying.

‘You’ve been very bad,’ repeated Jude. ‘And if you don’t stop your terrible behaviour, we’ll be forced to return – and you won’t like it if we do.’

Robbincon blinked at her. ‘You’re not going to turn me in? You’ll just come back and … talk to me again?’

Jude tried not to smile – she loved it when people fell into their trap. Occasionally, the arrival of ‘magic-keepers’ was enough to make people promise they would never dabble in illegal magic again. But more often they came across people who questioned them.

She pretended to cough, slipping the lifting magic into her mouth. Beside her, she knew Moorley had done the same. This magic was slimy and it made her whole body feel warm. She and Moorley both lifted a finger and Robbincon rose from his chair, flying back and crashing against the wall – not with enough force to hurt him, but enough to scare him. This was magic they had picked up on one of their first missions, and though it was largely harmless, it worked well to get people to fall in line.

‘Magic-keepers work outside the law,’ said Jude, her arm shaking with the effort. ‘Next time, we’ll do worse than just talk to you.’ Though the magic was holding Robbincon up and she wasn’t lifting him by herself, a sharp pain shot up from her fingers to her shoulders. It was a horrible side effect, which was probably why the magic was illegal. Also the lifting magic was starting to churn her stomach and she was currently fighting the urge to throw up. That would ruin their disguises pretty quickly.

Robbincon’s arms were splayed on the wall and he gave a large gasp. ‘OK,’ he said. ‘I promise. I’ll never do anything like this again. I won’t even complain to your department...