YOU KNOW WHEN you go Easter egg hunting and you have a hunch where an egg is going to be right before you find it in that very spot? I had that feeling. Like someone had put a little treasure down there for me to find.

      Not only that, but it had been there my whole life. Waiting for me.

      I felt exhausted and terrified, as wrung out as an old sock stuck in a spin cycle for too long. Yet I sank to my knees and peered closer. The thing in the slab was brown and papery. I could only see the top of it, but it looked like a leaf.

      And here was the weird thing. Even though the sensible part of me was jumping up and down with disbelief – what was I doing, trying to rescue a random leaf, when I should be inside, running for cover before another earthquake? – there was another part of me with different ideas. And it seemed to be winning the battle of wills, because there I was, sweaty and hot and obsessed with jabbing my fingers into a broken concrete lump so I could pull this thing out.

      Then it glowed.

      I stared at it. I rubbed my eyes. Engaged the old eyeballs again. But no – it was not glowing now. Yet for a second it had looked almost alive …

      All of a sudden, I didn’t care about my homework. I didn’t care about my schedule. I didn’t even care about my school trousers getting dirty. I eagerly reached down. But my fingers were too wide and it was wedged at least fifteen centimetres too deep. My fingertips scrabbled desperately but touched only air.

      I ran into the kitchen, yanked open a kitchen drawer and rummaged around with shaking hands. What I needed was something narrow and sharp to stick down the crack and fish out what was down there. Barbecue tongs? No, they wouldn’t fit in the gap. A cocktail stick? That could work!

      I ran back outside, kneeled down on the paving slab and poked the cocktail stick down the gap. It fitted perfectly but wasn’t long enough. I could have cried with frustration. I didn’t know why it mattered so much. I was spellbound somehow.

      I hurried inside, pulled open the second kitchen drawer and found a yellowing plastic wallet stuffed with paperwork and a roll of cling film. Great if you wanted to cling-film some paperwork; less great if you wanted to impale something inexplicable your patio had just thrown up.

       Forget your little rescue mission. Just get back to your schedule and make up for lost time.

      I went to retrieve Mr Grittysnit’s letter from underneath the willow tree and threw a final glance at the cracked paving slab. That was weird. The thing stuck down there seemed to have … moved.

      I could see a brown corner poking out now. That would make it much easier to pull out. But hadn’t it been wedged so far down my fingers hadn’t been able to touch it?

      At that point, I could have done the sensible thing. Walked back into the house and called the emergency services. Reported an Unidentified Brown Papery Thing and had it removed by the authorities. Lived off the excitement for a couple of weeks, and then got on with my life.

      But I didn’t.

      And that is something I have to live with for the rest of my life. And potentially, although it’s very unlikely, so will you. But let me offer you an important bit of advice just for your peace of mind.

      If you are in any way changed by this book, you may feel, at first, like blaming me. But you’re going to have to push past that, seriously. Blame is a toxic emotion that will only, in the end, make you suffer, not me. So remember. No blame. No hate. Aim for brave acceptance instead. I offer you this advice as a friend. Or you could always try punching a pillow – apparently that helps.

      Where were we? Oh yes. Shivering a little in the shadows, I looked again. I was right – the old papery object had moved. The top half of it now stuck out of the slab completely. How had that happened?

      My brain leaped ahead of me, desperate to provide answers. Perhaps there was another tremor when I was in the kitchen just now and the shockwaves made it move?

      I bent down and reached. As the tips of my fingers brushed the object, a jolt of energy ran all the way up my arm, like tiny electric shocks skipping up my bones. For a second, a vision flashed in my brain. Bright green grass, damp with dew. A tangle of tree roots.

      I pulled the entire thing free, and straightened up. It was in my hands, so light it was almost weightless.

      I stared at it eagerly, wondering what treasure I had discovered.

      It was a …

      … brown paper envelope.

      A brown paper envelope, ladies and gentlemen.

      Disappointed yet also completely mystified, I brushed the earth off it, revealing some curly writing on one side which said: THE SURPRISING SEEDS. The words were scrawled in faded, old-fashioned green ink.

      Underneath that was the sentence SELF-SEEDING BE THESE SEEDS.

      I turned the packet over, hoping to find more explanation, or at least something a bit more exciting, but there was nothing.

      No instructions.

      No use-by date.

      No picture.

      No hashtag.

      Not even a barcode, for crying out loud.

      I shook it with frustration. Something rattled inside.

      I shook it again. It rattled again. Yikes.

      There was no way I was going to open that. Who knew what might come scuttling out? Instead, I held it up to the late-afternoon sky. The light shining through the flimsy paper revealed about thirty small black things inside.

      These things had small, round black bodies, out of which grew four thin black stalks. They weren’t moving – they looked as if they’d dried up a long time ago. But they were spooky. Even their not moving was kind of frightening.

      Here’s a list of the things they looked like:

      1. Small, petrified jellyfish.

      2. Aliens with no faces and four legs.

      3. Dried-up severed heads, with mad hair.

      I stared at them again. They seemed to be waiting for me to do something. But what, exactly?

      My cheeks burned. Mixed in with my fluttery sense of revulsion was a feeling of being tricked. It was like discovering that something I thought would be exciting wasn’t, after all. Our Year Three class trip to the Little Sterilis dishcloth factory, for instance. (Take it from me: not the adrenaline-fuelled ride it sounds. And a very limited range of gifts in the gift shop, if you know what I mean.)

      I crumpled the packet up in my hand, scooped up Mr Grittysnit’s letter, stomped back inside and locked the back door firmly.

      Because – and pay attention, folks, for here is an important life lesson at no extra charge – if you want to protect yourself from a mysterious dark magic against which you are totally defenceless, then bringing it into your home and locking the door, thereby locking yourself in with it, is definitely the right way to go about it.

      Like I said, on the house.