Max and Kensy were still reeling from the fact that they had just cracked Britain’s greatest diamond heist and another jewel theft that would undoubtedly go down in the annals of history. Pity no one would ever know about it.

The children crossed the road to number thirteen, but just as Kensy was about to hit the buzzer, Max grabbed her hand. He shook his head and pointed at the silhouette in the top-right window. ‘That’s not Song. They’re too bulky.’

‘What if he’s in there and he’s been hurt?’ Kensy whispered. ‘Shouldn’t we try to help?’

Max heard footsteps just inside. He motioned to his sister and the pair leapt over the balcony railing and down to the basement entrance below, where they huddled under the steps. The front door opened and footfalls sounded on the walkway above. The twins held their breaths.

‘No, the butler’s not ’ere and the kids aren’t either,’ a man growled. ‘’Ow on earth did you lose them out of the back of the taxi, you blinkin’ bozo? The boss will not be ’appy.’

Max squinted through a small gap between the step treads but could only see the back of the man’s head. He appeared to be talking on his phone.

‘We’ll meet back at HQ. Might ’ave to lie low for a while,’ the man continued, and hurried across the footpath, where he hopped into the driver’s seat of a black cab.

Kensy waited until the vehicle disappeared around the end of the road near the Thames before he spoke. ‘Do you think all the taxi drivers in London are bad guys?’ she breathed.

Max shook his head. ‘I don’t know, but let’s go to the Beacon. I’m pretty sure Dame Spencer can help us.’

The pair ran up the steps and along the road in the opposite direction to the taxi. They didn’t stop until they reached the newspaper’s offices. Luckily, the security guard recognised them from their previous visit and let them straight through. They skidded across the polished floor to the reception desk.

‘Please, we need to see Dame Spencer,’ Max panted.

The young woman smiled at them brightly. ‘I’m terribly sorry, but she’s not available at the moment. I can take a message.’

‘But we have to see her,’ Kensy insisted. ‘It’s a matter of life and death.’

The woman gave the eleven-year-old twins a look not dissimilar to that of the policeman outside the Tate. She held up a finger as she turned away to answer the phone. Kensy, noticing people coming and going via the staff entrance, nudged her brother and pointed. Without a moment’s hesitation, they tailgated two young fellows through to the other side.

Max spotted a harried-looking man carrying a stack of papers coming out of the stairwell. ‘Quick!’ he said, sprinting towards it. He slid his foot inside just before it clanked shut. ‘Ow,’ he complained, rubbing his ankle.

The pair charged upstairs. Once they reached the thirteenth floor, the twins peered around the door. When all was clear, they slipped out and found themselves at the far end of the hallway to Dame Spencer’s office. They ran for it, their feet thudding and squeaking against the marble floor.

‘Max!’ Kensy gasped, skidding to a halt. She pointed to the portrait of Dominic Spencer. ‘He looks like Dad.’

Max reached into his blazer pocket and pulled out the newspaper clipping he’d found that morning. ‘I was going to say that the last time we were here, but Sidney interrupted us,’ he said, and held out the clipping for her to see.

Kensy looked at the photograph of the well-dressed man and woman and the two young boys standing in front of them. ‘That’s Dad,’ she said, frowning. ‘And Dame Spencer and that man on the wall … Are they …?’

Max nodded. ‘Think about it, Kens – the book at Alexandria. EDS, Edward, Dominic …’

‘She’s not in,’ a man said.

Kensy and Max spun around. ‘Fitz!’ they cried, barrelling towards him.

‘I’m sorry I didn’t find them,’ the man said. He shook his head and wiped the tears from Kensy’s cheeks. ‘There’s no trace.’

When the children finally let go, they looked at one another, a silent agreement passing between them.

‘Don’t worry, Fitz. We know they’re okay,’ Max said. ‘They sent us a message.’

Fitz’s brow furrowed. ‘How?’

Max patted his watch.

‘Oh, thank heavens,’ Fitz said, and the twins could feel his relief.

‘You can’t tell anyone,’ Kensy said. ‘Mum and Dad were very clear. And you’re the only person we can trust, although we’re not even sure about that, considering how much you’ve lied to us.’

Max crossed his arms, his eyes hardening. ‘Kensy saw you here when we came to meet Dame Spencer. I wasn’t sure at the time, but it was you, wasn’t it?’

Fitz exhaled. ‘Yes, but I can explain. That really doesn’t matter now but there’s something else that does.’ He glanced down the hall at Cordelia Spencer’s office.

‘It’s okay,’ Kensy said. ‘We know Dame Spencer is our grandmother.’

Fitz’s eyebrows jumped up in surprise. ‘Now, how did you two work that out?’

Kensy grinned, looking chuffed with herself. ‘That portrait over there is a pretty good start. Max and Dad are the spitting image of Dominic Spencer, wouldn’t you say?’

‘I found a book at Alexandria with an inscription in code,’ Max added. ‘We worked it out. Even though the name wasn’t exactly the same, I know it was Dad’s.’

‘This confirmed it.’ Kensy held out the photograph Max had found that morning. ‘That’s Dad, isn’t it?’

‘When we met Cordelia the other day, she wasn’t exactly friendly and seemed to want nothing to do with us,’ Max said, looking into the man’s grey eyes. ‘Why doesn’t she want to know us? Did we do something bad?’

Fitz took a deep breath and shook his head. ‘Never. We’ve got a lot to talk about, but this isn’t the place for it. Let’s get you two back to school, or Magoo will be calling the police,’ he said, and ushered the children to the lift. ‘I promise to tell you everything once we get there.’

‘Well, we’ve got some stories to tell you on the way too,’ Kensy said, and Max nodded.