Autumn yawned and rubbed her tired eyes. She’d finally given up and gone to sleep just after two, but the sound of machinery outside the window had woken her before dawn.

Kensy rolled over in her bed and snuggled down under the covers, trying to block out the noise. ‘What is that?’ she mumbled. She’d been dreaming of her parents and wanted desperately to fall back to sleep.

Autumn hopped out of bed and walked to the window. In the predawn light, she could see three men in chest waders – the sort fishermen wore – standing in the fountain. Two were pushing brooms through the water while the other was holding the end of something that resembled a giant vacuum cleaner. ‘They’re clearing the coins,’ she said. ‘Mr Reffell mentioned they do it three times a week and the money goes to the church to look after homeless people.’

Kensy pulled the duvet higher. ‘Seriously, that machine sounds like a tree mulcher. I’m so tired.’

After dinner, the children had convinced Mr Frizzle to have an early night. The man hadn’t minded at all, given they had to be up at the crack of dawn to take the train to Pompeii for the day. The four children had returned to Kensy and Autumn’s room and spent until lights out working on the code together without success. Autumn and Kensy had continued their efforts after the boys had left, but many hours later the girls were still nowhere close to solving it.

Autumn was just about to go back to bed when she suddenly noticed something. She squinted to make sure. ‘Kensy, come here. You need to see this.’

The girl’s feet hit the floor with a thud. Her mind was still roiling after everything that had happened yesterday. Kensy pushed her hair out of her eyes and walked to the window. The piazza was almost empty save for the men in the pond and a fellow who was pushing up the shutters on a coffee shop.

‘Do those guys look familiar to you?’ Autumn asked.

Kensy gasped. ‘They’re the thugs who were chasing us. From the orphanage.’

Autumn nodded. ‘That’s what I thought.’

There was a knock on the door and the girl scampered over to answer it. Kensy’s eyes were glued to the trio down below. She couldn’t believe anyone would entrust them to clear the money. They probably kept it for themselves.

Max and Carlos hurried into the room. ‘We’ve got it!’ Max waved a tired-looking piece of paper in his hand. ‘We know what the code says!’

Kensy spun around. ‘Well, out with it,’ she demanded.

Max took in a deep breath. ‘Proof of life and then I will do as you ask.’

Kensy’s eyes widened. ‘What?’

‘That sounds like a ransom,’ Autumn said, her brow furrowing.

The boys nodded. ‘Our thoughts exactly,’ Carlos replied.

‘Should we tell the teachers?’ Kensy asked. ‘I mean, if the Prime Minister’s son has been kidnapped, we can surely do something.’

There was another knock at the door. Autumn answered it again and was surprised to see Miss Ziegler.

‘Do you know where Max and Carlos are?’ the teacher asked. ‘I was waking everyone up as we need to be on our way to the train by six-thirty and their room was empty.’

Autumn opened the door wider. ‘They’re here. They only just came up, but we need to tell you something.’

Lottie walked into the room. One side was immaculate while the other looked like an explosion in a clothing factory. She didn’t have to think too hard to work out which of the girls the mess belonged to. ‘Good morning,’ she said, eyeing the group warily. ‘You know you boys shouldn’t be up here. Mr Reffell might have a heart attack if he knew girls and boys were in each other’s rooms – even if two of you are brother and sister.’

She spotted the piece of paper on the end of the bed. ‘What’s this?’ She picked it up and studied the markings. ‘Good grief, this is a pigpen cipher. Where did you get it?’

And with that the children launched into the story of everything that had happened the past afternoon and where that note had come from.

Lottie Ziegler twisted a stray curl around her finger. ‘We need to call it in and see if there’s any intel on Nico. But you do realise that, if there’s nothing, we have no role to play. We can’t go around getting involved in matters that are none of our business.’

‘But Nico’s been kidnapped,’ Kensy said, appalled by the woman’s indifference. ‘We saw his mother – she was praying and crying. She lied to a priest!’

‘You don’t know that for sure – there were photographs of the reunited family on the front page of the newspapers. There was even something in yesterday’s Beacon – I read it myself,’ Lottie countered.

‘What if that picture was old?’ Carlos said. ‘They could have supplied it to the press to make them think he was back.’

‘That’s true,’ Max said. ‘Maybe we can find a copy of one of the local rags downstairs.’

‘I don’t think you should get too worked up.’ Lottie walked to the window and looked down into the piazza. ‘It might be something else entirely. The woman has quite a few troubles at the moment and Italian politics have always been tricky. Trust me. I’ll see what I can find out, but if there’s nothing, I suggest you forget about it and enjoy the rest of the trip.’

Max sat down on the end of Autumn’s bed. ‘I was kind of hoping we’d get to test our skills on a proper mission.’

‘Me too.’ Kensy couldn’t help feeling a little miffed that, when she’d said as much on Christmas Day, her brother had sided with her grandmother against her.

Lottie looked at the lad and smiled kindly. ‘I know you’re keen, Max, but believe me when I say you’re not ready yet. And when you do find yourself in the middle of something, sometimes you’ll wish you hadn’t. Our line of business isn’t exactly straightforward. Carlos and Autumn have been training for years and they haven’t had a lot of field action, apart from rescuing you two in London, but one day, when you least expect it, everything you’ve learned will come in very handy. Now, hurry up and get dressed. It’s almost six and you need to have some breakfast. The fast train to Naples leaves at seven-thirty and Mr Reffell wants us out the door in half an hour.’

Max placed the newspaper on the table. Miss Ziegler had handed it over as they’d hopped aboard the train. The journey from Rome would take just over an hour, then they’d catch a local service from Naples to Pompeii. Max, along with Carlos, Autumn and Kensy, studied the picture of the Prime Minister and her husband and son. It appeared to have been taken on a balcony at the Palazzo Chigi and in the background they could see the Christmas tree and a glimpse of the protestors too.

‘So much for that theory,’ Max said with a sigh.

Kensy’s forehead was fixed in a permanent furrow. She realised she’d been so caught up in thinking about the Prime Minister for the past fourteen hours that she’d forgotten about her parents. A sharp stab of guilt hit her in the chest. What if, with all that distraction, she and Max had missed something important? As Max looked across at her, his mouth set in a grim line, she wondered if he could read her mind.

In the group of four seats across the aisle, Misha and Lola were doing their best to ignore Alfie and Graham. Graham was reading a book on space travel and Alfie had a rugby magazine open. Lola was harping on about her previous evening’s purchases.

Kensy glanced across at Misha, who crossed her eyes in boredom. Lola caught sight of Kensy’s attentions and sneered. ‘What are you staring at?’ the girl said loudly.

Kensy shook her head. ‘Nothing.’

‘You were watching me, weren’t you? You’re always watching me.’ Lola pulled a face and sniggered.

‘No, I’m not,’ Kensy said crossly.

Sensing trouble, Max tried to shoot his sister a warning look, but she refused to meet his eye.

‘Yes, you are. You’re doing it now.’ Lola pretended to shiver and looped arms with Misha. ‘It’s so creepy.’

Kensy rolled her eyes at Autumn, who twisted her mouth to stop herself from giggling. ‘Lola, I can assure you that I am not watching you and I don’t want to be you and I don’t think you’re the most mesmerising girl on earth,’ she said as nicely as she could.

Lola’s eyes narrowed. ‘Did you just call me ugly?’ Her bottom lip began to tremble. ‘Misha, say something!’

‘Stop being mean to her,’ Misha blurted, although, for the first time since Kensy had known the girl, her words were a little less than convincing and Lola must have felt it too.

Lola’s head swivelled sharply. ‘Whose side are you on?’

‘Yours, of course,’ Misha replied. She turned to Kensy and shouted, ‘Leave her alone!’

‘Okay.’ Kensy raised her palms in surrender, then glowered out the window.

Max couldn’t shake the feeling that something was up with Misha. The girl seemed to have the weight of the world on her shoulders. He’d have to talk to her later, presuming they could get a minute alone without Lola lingering like a bad smell. ‘I’m going to the kiosk to get a drink,’ he said, standing up. ‘Does anyone want anything?’

‘I’ll come,’ Kensy volunteered. She hoped no one else joined them as she really wanted to speak to Max alone. Autumn asked her to bring back a bottle of water.

‘I think I saw Dad,’ Max said quietly, once the pair had entered the next carriage.

‘What?!’ Kensy exploded, garnering glares from anyone within fifty paces. ‘When?’

‘Keep it down,’ Max hissed.

‘Why didn’t you tell me?’ Kensy demanded. ‘I can’t believe you kept that to yourself.’

‘It was when those guys were chasing us yesterday, but then he disappeared into the crowd and I couldn’t see him any more,’ Max explained. ‘Maybe it wasn’t even him. Maybe I just imagined it.’

Kensy could hear the pain in her brother’s voice. She knew she should give him a hug or show some sort of kindnesss, but she was still mad that he hadn’t told her sooner. ‘I can’t stand all this waiting. What could they possibly be doing for this long?’

Max nodded. ‘I’ve been thinking that the only thing that would be keeping them away from us is family.’

Kensy looked at him in a way that suggested he had a screw loose. ‘But we’re their family, and Granny and Fitz and Mim.’

‘And Mum’s parents,’ Max said. He stopped and looked his sister in the eye. ‘What if they aren’t dead – have you thought about that? What if they’re the reason Mum and Dad and Fitz disappeared in the first place?’

Kensy thought for a moment. It made a strange sort of sense.

‘There’s a computer in the business centre at the hotel. Tonight, when everyone’s in bed, let’s see what else we can find out about them,’ Max said.

Kensy reached out and pressed the button to enter the dining car. ‘Meet you there at midnight.’