‘No!’ Mr Reffell held up his shield to defend himself from the hordes of tourists trying to take a photograph with him. ‘No more pictures, please. We’re in a hurry!’

The man extricated an old lady from his waist and wriggled free from another’s grasp.

‘Do you really think it was a good idea to dress up as a Roman centurion, sir?’ Alfie said.

Monty Reffell straightened his helmet and threw his cloak over his shoulder. ‘Yes, it’s a perfectly good idea and you’ll thank me once we get to the Colosseum. You’ll see. There’s method in my madness.’

‘I thought there was just madness in his madness,’ Autumn whispered to Kensy, who giggled.

‘You should’ve charged all those people who’ve been stopping us for photos, sir, you’d have made a fortune,’ Dante said.

Elliot Frizzle smirked in agreement. Unlike Monty Reffell, whose choice of outfit fell squarely into the category of fancy dress, Elliot looked rather sharp this morning in a raspberry-coloured suit paired with navy suede shoes and a matching fedora. He could easily have passed as one of the stylish locals, which Mr Reffell might have been aiming at but only if it were a thousand years ago.

Monty rolled his eyes and bustled forward, picking up the pace in the hopes that they’d be able to tackle the last kilometre without any further disruptions.

Romilly Vanden Boom had almost choked on her cornflakes when the man arrived at breakfast, though that extra suitcase that clanked and thumped each time it had been moved now made complete sense. She did concede it was a magnificent costume and even better than the one he’d worn while promoting the trip at the school assembly. Lottie Ziegler was very glad he hadn’t conned her into dressing up this time too – she didn’t mind it at school, but in public was a whole other ball game. You never knew when you might meet someone interesting or madly handsome.

The walk from the hotel to the ancient amphitheatre should have taken around half an hour, however, with all the interruptions, it was almost twice as long before they rounded the corner near the magnificent Altare della Patria, which commemorated Victor Emmanuelle, the first unifying leader of Italy. With its bronze horses and winged chariot drivers atop the giant semicircular marble structure, the children couldn’t help but gasp.

‘That building is seriously stunning,’ Sachin mumbled, to the nods of his classmates.

‘And that one is even more amazing!’ Yasmina pointed down the road at the Colosseum in the distance.

‘Rome is like taking a trip in a time machine.’ Inez sighed. ‘It’s everything I’d hoped for and so much more.’

The smile on Monty Reffell’s face couldn’t have been any wider as they continued along the road, past the temples and ruins and the incongruous new metro station. Being a lover of history, and knowing that his students had caught the bug too, was incredibly gratifying.

‘Why don’t they fix more things up?’ Lola asked, sweeping her arm in a wide arc. ‘It’s all so old and crumbly. You’d think they’d want it to look nice for the tourists.’

Monty blanched. ‘Lola, these buildings and monuments are constantly under repair.’

‘Well, they don’t do a very good job then,’ the girl replied.

Misha shook her head vigorously. ‘No, not a very good job at all,’ she parroted.

She was so convincing that Kensy almost told her off, which made her stop to wonder whether she should scold Misha in an effort to keep up the whole pretence. It was all a bit confusing. Kensy decided to leave it for another time.

As the group drew closer to the Colosseum, they realised that the crowd was enormous. Against the backdrop of the imposing structure, it had been hard to tell exactly how many people were about. Romilly and Elliot disappeared among the throng to fetch their tickets. Meanwhile, the children arranged themselves in various configurations for pictures in front of the amphitheatre with their very own centurion.

‘So why did you dress up, sir?’ Alfie asked.

‘See those men there?’ Monty pointed at another group of soldiers. ‘They earn their living by harassing tourists, taking pictures with them and then demanding obscene amounts of money. I heard the going rate is fifty euros. It’s highway robbery!’

‘Wouldn’t they be upset with you encroaching on their turf?’ Max asked. He could see four men pointing their way and none of them looked very happy.

‘Too bad. I don’t mind if they harass everyone else, but I want them to leave us alone and my tactic seems to be working perfectly well.’ Monty nodded, feeling pretty pleased with himself.

Except that it wasn’t working well at all. The four men had now become eight and they were clearly about to make themselves known.

Carlos pointed over Mr Reffell’s shoulder. ‘Sir.’

‘What’s the matter, Rodriguez?’ The man turned and, before he could say another word, one of the burly gladiators jabbed a stubby finger in the centre of his chest.

Cosa fai?’ the man spat.

Monty gulped. ‘Dressing up for the children,’ he replied. ‘It’s not against the law.’

‘That is our domain,’ another man shouted, waving his fist in the air.

‘Well, I don’t see I’m doing any harm,’ Monty said, right before the burliest member of the group grabbed him by the throat. Monty began to make choking noises, ostensibly in the hope that his attacker would release him. He wasn’t supposed to retaliate in front of the children, but if the fellow didn’t desist soon, he would be left with little choice – and there was a part of him that was itching to have a go. ‘Please,’ he coughed. ‘That is very unpleasant.’

Kensy marched forward and stamped heavily on the perpetrator’s sandalled foot. ‘Let Mr Reffell go!’ she demanded.

The man yelped in pain and released his grip, then began jumping around, clutching his injured toe. The rest of the children were stunned but mostly impressed.

Monty Reffell drew his plastic sword. ‘I challenge you to a duel!’ he cried, and was met with laughter. ‘I don’t see what’s so funny. I am an excellent swordsman.’

Stupido,’ the shortest of the group said, chuckling.

‘I am not stupid, I can guarantee you that,’ Mr Reffell said, drawing himself up to full height.

Max spotted a policeman and nudged Autumn. ‘I think perhaps we need to defuse this, don’t you?’

Autumn nodded. ‘Good thinking.’

They took off across the piazza.

Mi scusi!’ Max called to the uniformed man. Then, with a fair amount of arm-waving and grammatically incorrect Italian, he managed to tell the officer exactly what was going on – except that he might have left out the bit about his teacher dressing up as a centurion to try to outsmart the actors. ‘Those men over there are demanding a fortune for a photograph and we’re just innocent children,’ Max blurted.

The policeman was off after them like a shot. Although the centurions weren’t doing anything illegal, as they were registered street performers, the constabulary were stationed around the building to protect tourists from being ripped off and it sounded as if the children were being held for ransom.

Allontanatevi dai bambini! Get away from the children!’ the policeman shouted, sending the centurions scattering.

Mr Reffell rubbed his neck, wishing that just once he might be able to put all those years of martial arts training to good use. Unfortunately, it was against company policy unless absolutely necessary. A good old sword fight would have sufficed. He then spent several minutes trying to explain to the officer that he was with the children. Even then, it didn’t stop the policeman from issuing him an on-the-spot penalty for not having a permit to dress as an ancient figure in a public place.

Luckily, Mrs Vanden Boom and Mr Frizzle appeared with the tickets and their guide, a middle-aged woman with a pixie cut and a powerful voice. As the children followed their teachers through the entrance, Kensy looked up and gasped.

‘Max!’ she shouted, charging towards her brother. She knocked him sideways to the ground as a stone the size of a car battery shattered onto the ground, sending the tourists scrambling. Carlos and Autumn ran to Max’s aid as the rest of the group disappeared inside the Flavian ampitheatre. Kensy stood up and dusted herself off.

‘Are you two okay?’ Autumn gasped.

Max’s heart was pounding, but he wasn’t hurt. The stone had hit the ground exactly where he’d been standing moments before.

Kensy stared up at the building. For a second she thought she’d seen a face in one of the openings, but then it was gone.

Carlos offered Max his arm.

Inside the Colosseum, Lottie Ziegler had done a quick head count and realised there were four students missing. She hurried back to the entrance and was surprised to see Carlos helping Max to his feet and rubble on the ground around him.

‘What happened?’ she asked urgently, looking left and right.

Max stood up and scratched his head.

Kensy had no idea why she’d looked up when she did. Luck maybe? A mere coincidence? Perhaps she’d heard something and didn’t realise it. She hated to think about what shape her brother would be in if she hadn’t seen that stone. Kensy licked her lips and swallowed hard. ‘I think someone just tried to kill Max.’