She laughs and looks at Liam, who is at the edge of the pod. ‘I like this girl,’ she says to him. ‘She tells it like it is.’
I sigh impatiently. We are nearing the top of the ride, and will soon start our descent. We don’t have a lot of time. ‘Who is “we”, anyway? And where did you get your tattoo?’ I ask.
‘That’s a whole lot of questions, Agatha.’ A long pause follows.
I huff. ‘I thought you were going to start giving me answers.’
She smiles. ‘I was, but Liam being here as well has … Well, it’s thrown me a bit.’
‘Whatever you want to say, you can say in front of my friend.’
‘I’ll have to take your word for that …’ She takes a deep breath, as if thinking it all through, and then she seems to come to a decision. ‘The tattoo,’ she starts, ‘is a symbol for an organisation – a secret organisation – called the Gatekeepers’ Guild.’
I force my face to remain expressionless but an electric tingle shoots down my spine at the mention of that name – the name from the secret tunnel.
‘Some people carry the symbol in their wallet, or have it sewn into the lining of their blazer. Wherever they feel it’s discreet.’ She arches her eyebrow at me. ‘Personally, I wanted something more permanent, and since I wear long sleeves …’ She pushes her sleeve back to reveal the silvery tattoo – the one I first saw in the park that day.
‘Why now?’ I ask. ‘Why are you telling me all this? What’s changed since the hospital, when you pressed the emergency buzzer to have me evicted?’
‘Don’t you know?’ she asks.
‘No idea,’ I say, trying to reach deep into the recesses of my brain for something that seems to just be lingering there, struggling to make its way to the surface.
‘Well, you stumbled a little too close for comfort …’ The professor folds her hands neatly. ‘So, to keep it brief – the Guild has members all over London. Gatekeepers, both literally and figuratively. The majority of our members, in their roles as caretakers, housekeepers, butlers and so on, hold keys to the ancient buildings that are an integral part of London.’
‘Waiters too?’ I raise an eyebrow, thinking how Mr Worth had handed me that letter at the Orangery.
‘Perhaps,’ Professor D’Oliveira says. ‘Anyway, these buildings, and their grounds, offer access to the tunnels that run all over the city beneath its inhabitants’ feet.’
I think about Dad’s rack of keys that open all the grilles and gates in the park. ‘So … Dad? Is that why he has so many keys?’
She shakes her head. ‘Not your father. He was never a member.’
I open my mouth to ask ‘then who?’, but she holds up a hand to silence me.
‘I don’t have time for all of your questions right now, but let me at least explain a bit more, and then you can ask later.’
I nod as Professor D’Oliveira starts again. ‘The Gatekeepers are custodians of this country,’ she says, ‘and have been for centuries. We’re secret agents. We get the cases that MI5 can’t solve. When everyone else is stuck, we step in.’
I suck in a deep breath as she looks me in the eye. ‘What you saw – the assault on my person in Hyde Park – has put you in danger. Now, I need you to listen to me, and do as I say.’
‘And why should I trust you? How do I know that you’re on the right side in whatever’s going on?’
She laughs. ‘Because there’s no one else you can trust to help you.’ She leans in more closely to the camera. ‘The truth is, you can walk out of here and pretend that this chat never happened, but then you’d be on your own. And believe me, the people who are coming after you are a whole lot tougher than me. What you saw – well, that’s just the start.’
‘Why are you telling me all this?’ I ask. ‘Why would your secret organisation bother itself with a thirteen-year-old girl?’
The professor doesn’t say anything. She just stares at me. She isn’t telling me something, but I feel like I already know what it is. The key stashed in my room, the clues left for me to find – all from Mum. She wouldn’t have left them for me if she thought they would lead me into danger. She left them because she wanted me to find out about the Guild.
‘My mum,’ I say. ‘My mum was a member, wasn’t she? She was a member of the Gatekeepers’ Guild!’
The professor has closed her eyes. Even over the scratchy intercom, I can hear her take a deep breath.
‘Your mother was one of our agents, yes,’ she says quietly. ‘One of my agents. The best.’
The pod seems to contract around me. The view of Parliament and the river swims dizzyingly. There’s a roaring sound in my ears.
‘What?’ My voice has gone very small.
The professor nods. ‘Clara was incredible. Does that really surprise you?’
‘No, but …’ I remember the key round my neck. ‘Well, it’s a shock.’
‘I’m sure. But it’s the truth.’
‘So can I join and take her place?’ I ask, feeling a lump rise in my throat. Where did that come from? The words were out of my mouth before I had time to think about them.
Professor D’Oliveira’s eyebrows shoot up. ‘It’s not as simple as that – there isn’t anyone as young as you in the Guild, for starters, and, even if there was, there are tests to complete.’
‘Tests? What kind of tests?’
‘Enough for now …’ Professor D’Oliveira spoke. ‘We can’t just let anyone into the Guild.’
I cross my arms. ‘But I’m not “just anyone”.’
‘I can see that. And perhaps some day that will change, but in the meantime I’m asking you not to meddle – to leave it to the experts to deal with this crisis.’
‘You mean … the water? The red slime?’
She frowns, saying nothing, but for a secret agent she’s quite transparent.
‘I knew it! I knew it wasn’t just an accident!’
‘Agatha, listen to me – you need to forget what you know.’
Forget what I know? How can I do that?
‘Agatha, we have to get off in a moment,’ says Liam, eyeing the ground below as the capsule slowly approaches the end of its circuit.
‘Yes, and this is the end of our conversation for now,’ the professor says.
I feel as though I’m going to cry with frustration. I’ve learnt so much but at the same time, so little. I force the tears back.
‘One last thing, Agatha – look after your father. He is too trusting.’
The screen goes blank.
Then it switches on again. ‘Oh, and, Agatha?’
‘Yes?’
‘Stay out of our tunnels.’
The intercom shuts off for good. The pod draws level with the ground, and the steward asks us to step off. Liam and I move away from the wheel.
‘Well, that’s that,’ he says.
‘What’s what?’
‘The end of your investigation.’
‘What?