Max and Curtis ran up the stairwell, trying every door on each level of their ascent.

‘What about picking a lock?’ Curtis asked. He wondered why neither of them had thought of that before, then realised there was no mechanism on any of the handles. ‘Okay, scratch that idea.’

‘Don’t worry, I’d already checked,’ Max said. ‘And I know how we can get out – we’ve just got to move fast.’

The boys charged to the top of the stairs and Max spotted his target – an air-conditioning vent. If they could somehow haul themselves inside the ducting, they’d be able to get back into the building. It was their only hope.

Curtis looked up, assessing the height of the vent. He and Max were both way too short to reach it.

Max leapt onto the metal railing, balancing precariously as he stretched up to the ceiling. He swiped with his arm but his fingers didn’t go anywhere near close enough to grip the metal.

‘We need something to extend your reach,’ Curtis said.

Most days that wouldn’t have been a problem, but the Pharos students had been stripped of all devices by Mrs Vanden Boom and Mr Reffell prior to the competition. After all, none of the other students would have had the sort of advantages spy gadgets brought to the table. The boys had given up their Pharos issue tie clips that had a myriad of uses including holding a length of fine steel cable with a fastener on the end – which would have come in very handy right now.

‘What about a tie?’ Curtis said, then quickly realised that wouldn’t work. The fabric had no weight to it and the vent slats were too close together to be able to feed the garment through, even if they could manage to toss it that high.

‘Come on, think,’ Max muttered to himself. He reached up again and jumped for extra height. As he came back down, one foot slipped off the rail and he only just managed to stay upright.

‘These shoes are deadly,’ the boy moaned, thinking he needed to be barefoot to get extra traction. He was just about to kick them off when he remembered there was one piece of equipment the teachers hadn’t been able to take. Probably no one had thought of it anyway.

‘Shoes – that’s it,’ Max breathed. ‘Curtis, take one of your laces out – quickly!’

The boy did as he was told, though he wasn’t sure why. No one had ever mentioned that there was anything special about his shoes, though this would be a good time to find out.

‘Okay, what’s the deal?’ Curtis asked.

‘Watch and learn,’ Max said as he spun the lace around. It rotated at lightning speed before Max flung one end towards the ceiling. The thin cord stretched almost intuitively and reached for the metal grate, latching on. With one hard yank, the panel swung down on a hinge, low enough for Max to grab hold.

‘Whoa!’ Curtis gasped, his eyes wide. ‘That’s handy.’

‘Come on!’ Max pulled himself into the ceiling, then leaned back out and offered his arm to Curtis who hopped onto the railing and reached up. Within a few seconds the boys were both inside the vent. ‘This way,’ Max urged as they commando crawled along the silver ducting.

‘Are you sure?’ Curtis looked behind them, but it was hard to see with only pinpricks of light getting through.

‘Yes,’ Max said. ‘I had a look at the blueprints for the arena last week, just in case we needed to make a quick exit for any reason. It never hurts to have a plan.’

‘That was lucky,’ Curtis said as he followed his friend. He didn’t imagine that the National STEM Championships were a likely terrorist target, but he was glad Max had thought otherwise.

‘Okay, we’re here,’ Max said.

Curtis peered through the vent and did a double take. ‘You’re kidding, right?’ He and Max were perched high above the arena floor.

‘Nope, and don’t worry – those shoes have some other very cool features that are about to make this absolutely okay,’ Max said.

‘But everyone will see us,’ Curtis whispered as Max kicked open the grate and sat on the edge.

The lad pointed at the video screen below them. ‘No one will notice us behind that. I promise you’ll be fine. Just land on your feet, okay?’

‘Do I have to activate anything?’ Curtis asked. He knew Max wouldn’t lead him astray. If he could jump from the top of the Statue of Liberty, he could manage this – although on that occasion there had been the security of a parachute.

Down below the boys could hear the announcer.

‘Right, everyone’s teams are in order. No, wait. I see that Central London Free School appear to be two participants short. They’ve got about twenty seconds to make it back to the arena or unfortunately they’ll be disqualified for being unable to field a full complement – even with their reserve player,’ Riley Morton bellowed. There was a moan around the stadium and the boys could see Kensy and the others huddled together worriedly.

The headmaster of Central London Free School, Magoo MacGregor, was seated alongside his wife Tippie in the front row of the arena, having arrived at lunchtime to watch the afternoon’s proceedings. Mrs Vanden Boom had called the school to report that the children were doing very well and might likely make it to the finals, hence Magoo’s appearance. Romilly had been surprised to see Tippie, though, given the woman’s role heading up the Pharos Inventions Team, perhaps she was keen to observe the Central London Free students’ problem-solving abilities. The children were the future of the organisation, after all. Right now, Magoo’s face was red and he was directing a look of thunder at Romilly, as if it was her fault the boys were missing.

From his position on high, Max spied the lad from Bridgewater who had given them the bum steer. He couldn’t wait to wipe that smug look off the boy’s face.

‘Max, we’ve got to go!’ Curtis urged. He swallowed hard and wondered what on earth was about to happen.

‘I’m afraid it’s not looking good for our third team, folks. Ten seconds,’ Riley Morton boomed. ‘Nine, eight . . .’ he started a countdown, the crowd joining in with great gusto.

‘Where are they?’ Autumn whispered. She began to turn a circle, scanning the audience, when her eyes were drawn upwards.

‘Kensy!’ She grabbed the girl’s sleeve.

‘What?’ Her friend spun around and realised what Autumn was looking at.

Max leapt first. Curtis gulped, then closed his eyes and shoved himself off the ledge. He muttered a prayer and was bracing for impact when something miraculous happened. Just when his feet were about to hit the ground, there was a strange feeling of energy from below. A rush of air cushioned the landing and, while Curtis stumbled momentarily and grabbed Max’s shoulder, both boys remained upright. With seconds to spare they raced across the floor, appearing from behind the giant screen to join their team.

‘Well, I’m afraid –’ Riley began.

‘No! They’re here!’ Kensy yelled. ‘They’re back. They made it in time.’

Riley Morton looked over and realised that the girl was right.

‘Well, you two better have brought your A game for this last session – your team wouldn’t have been too happy with you if you hadn’t shown up,’ the man chuckled.

Max and Curtis grinned, though Curtis could still feel his heart about to burst through his chest.

Max clocked the Bridgewater student standing to his left, a sneer on the boy’s face. He gave the lad a grin and a slight nod of the head. ‘Good luck,’ he mouthed.