I think about the message – ‘You shouldn’t spy on people’. I remember hearing JP’s voice, calling out to my dad. He’s always been so friendly and unassuming, just living in the park. But could this be something to do with him? I realise how little I know about the mystery man. He came to live in the park a few months ago, and introduced himself to me. Dad went and talked to him and decided he was all right. But what did Dad know about him? What if JP has been spying on us all along?
I put the letter and the flower in evidence bags and put those up in my room. Then I clear up the flowers on the lawn – hopefully with everything going on, Dad won’t notice that someone has decapitated his plant. I brush my hands off and take a deep breath. I’m not going to be intimidated – I have to get to the bottom of what is going on.
I’m just coming in through the back door when Dad shambles into the kitchen, still wearing his pyjamas (which is unusual for him, even at the weekend).
‘Late night?’ I ask, putting on the kettle.
‘It –’ Dad pauses for a big yawn – ‘was.’
‘You had a visitor?’ I ask, trying not to sound too interested as I take two mugs from the cupboard and two teabags from the jar.
‘Mmph.’ Dad nods, sitting heavily at the table. ‘Just some bloke from the Environment Agency, wanting to know how the park is getting on in the drought.’
‘Oh, right. Did you tell him about your experiments?’ The kettle clicks and I pour it out (NO. 1 DAD mug for him and an Eiffel Tower souvenir mug for me).
‘Yeah, but there wasn’t much to say. It’s not like I know anything the Environment Agency doesn’t. We ended up talking about you, actually.’
‘About me?’ A chill runs down my back.
‘Yeah, just making conversation really. He said he has a daughter your age, and I was telling him that you want to be a detective when you grow up … Nice bloke, actually.’
I hand Dad his cup of tea, feeling queasy.
‘I, uh, I should go … Things to do.’
‘All right. Don’t forget your homework this weekend – you’ll feel better when it’s done.’
‘OK, Dad.’
I leave the kitchen and climb the stairs to my room. Perhaps the man’s visit was just a coincidence, but I have a bad feeling. And why was JP lurking outside our house when he left? There are many questions and few answers, but I can’t shake the sense that I’m being watched.
Gathering my thoughts, I go back to the mysterious key – what could it be for? What could it lead to? Whatever it is, it has to be important – Mum took the trouble to hide it, and left a coded message so I would find it. (Eventually, I think. I’m embarrassed at how long the key had lain there, undetected.) I pace the room, thinking over everything I know, but getting no further. I sit down on my bed and write a list of points in my notebook, which is filling up quickly –
1. The key was hidden, so it must be important.
2. If the key is important, it must open something.
3. Mum wanted me to find the key.
Tears prick my eyes, but I blink them away.
4. If so, she must have left something telling me what the key opens.
And yet – what can that clue be? I have no idea what the key might be for, or where I might find out. Then, out of the corner of my eye, I see something lying on the floor – a tiny slip of paper.
‘Of course!’ I shout, snatching up the bookmark that fell out of the book last night. In my excitement at discovering the key, I’d forgotten all about it. When I turn it over, I see it’s a tiny photo. The image – a grainy black-and-white shot barely bigger than a passport photo – shows a caged-off tunnel. A path leads down to a small opening covered by iron bars. I know that tunnel, and search my memory for a moment. I have it – it’s a tunnel in Hyde Park, at the edge of the Serpentine.
The tunnel must run right under the lake. I’ve always thought it was just some sort of drain.
‘Right,’ I say to myself, suddenly scared of what I know I must do next …
An hour later, I’m striding down to the caged-off tunnel, dressed all in black and wearing gigantic wading boots, with a torch in one hand and a gas mask in the other. The gas mask came with our cottage – it had been sitting in its box under the stairs since the Second World War, quietly gathering dust. I don’t know if it still works, but it will have to do. It’s all I have to protect me from the noxious fumes of the red gunge. Most importantly, I have a set of keys to the grating in my pocket. In Dad’s room, there’s a rack holding dozens of sets of keys, for all kinds of sheds, gateways and grates around the park. It took me a little while to find the right one for the grating. It was labelled Serpentine and Surrounds. None of the keys look like the mystery key round my neck, but some of them are very old.
I go down the short ramp to the grate and look around, but nobody is there to see me. People aren’t going out much, preferring to stay home and keep cool. Also, there are rumours that the red slime might cause all sorts of diseases if inhaled, so people are getting nervous about breathing in the city air. According to the news, thousands of people have left to go to the countryside, and sales of air conditioning have gone through the roof.
I try a couple of Dad’s keys in the padlock before I come to the right one. The lock clicks open in my hand. I take a deep breath and put on the gas mask. It smells musty, but I don’t have any choice – there could be more of the noxious red slime down here. Switching on the torch, I step into the tunnel.
The space is tiny – I have to crouch right down to move through it. The floor is muddy concrete, the arched tunnel made of crumbling brick. Though I can’t see any of the red slime yet, I can smell its familiar stink, and hope the gas mask is protecting me. I press on, not allowing myself to stop and think about what I’m doing. The tunnel seems to go on forever, until my legs are cramping and my neck stiff. The floor becomes muddier, and now there are pools of thick red algae. I tread carefully, my hand on the wall and my feet squelching in slime, but I can’t see much through the tiny circles of glass in front of my eyes. Suddenly, my hand misses the wall and my feet slip from under me.
I curse as I hit the ground hard. I’m covered in the cold ooze. It makes my hands sting – I wish I’d thought to wear gloves. The torch jolts from my grasp and hits the ground with a clunk. I’m terrified its bulb will blow and leave me in darkness, but the light stays on. I take a moment to make sure I’m not badly hurt. I’m more winded than injured. I collect my torch and get up again. It can’t be far now, I tell myself. On and on I go, becoming shaky and light-headed, as if I’m reaching high altitude, rather than a tunnel just a few metres below ground. Finally, the passage opens into a slightly taller tunnel that turns right. I stand, relief spreading through my aching muscles. Ahead of me is a narrow opening, like a doorway. When I shine the torch through it, no light bounces back – it must be a big cavern.
I take a deep breath, nervous but excited – I’m about to find something incredible, I’m sure.
Gripping the torch, I step though the gap, and out into –
Nothing.
I shine my light around, taking in the space. It’s big, that much is true. I’m standing in a vast arch of brick under the Serpentine. The roof is leaky, dripping gobbets of slime. The floor is covered in water and algae, completely unusable. The whole place feels empty and abandoned. I stand there for a minute, jaw clenched inside the gas mask – whatever I expected to find under the lake, it isn’t here. Was