Operation Liam Watch got under way the next day. Kat had set up a rota to keep tabs on him. Lolli and I were spending the weekend with Nana and Grandad so Mum and Dad could have a night away. It meant while I was off-duty I could go and help Grandad and check on the dragon-fruit tree.

The trouble was, things were still a bit awkward between me and Grandad. I got the feeling he knew something was going on with me that I wasn’t telling him. Every so often over the last few weeks I’d found him watching me, a thoughtful look on his face. Thoughtful and a little hurt, if I’m honest. It wasn’t going to be helped this time, with my head full of Liam and what he might be planning.

I found Grandad outside his shed talking to a jam jar. He gave me a nod and then tipped the jar to show me. It was full of ladybirds.

‘Just talking to the troops,’ he said. ‘Right, you lot, look lively. Dotty, Scarlet, Midge, Mrs Polka, I’m relying on you.’

He winked at me and released the latest battalion of bugs into the garden.

‘I’m hoping this lot’ll sort out my beanstalks,’ he said. ‘I might have a handful of giant pods, but the plants themselves are looking none too happy. In fact, you’d best look lively too, Chipstick – that dragon-fruit tree of yours is looking a bit sorry for itself as well.’

Horrified, I raced over to the tree. Grandad was right. The droop had got even worse. Some of the tendrils had shrivelled up, and although there were one or two fruits, it didn’t look a great crop.

‘What’s happened to it?’ I asked, my voice little more than a squeak.

‘Might just be needing extra water, but these exotic types can be a bit temperamental,’ Grandad said.

A horrible feeling squirmed in my belly like a maggot wriggling through one of Grandad’s pears. I’d tried to pay more attention to the tree after seeing how droopy it had been. But it was still struggling. What if somehow I’d done this? The tree had been fine until we’d cleared the garden – and until we had all started hatching our dragons. I’d always been so sure that Flicker’s fruit had dropped into my hand that first day. And that the same had happened with the others. But what if I was wrong? What if we’d taken the fruit before they were truly ready and we had damaged the tree in the process?

The squeak of a wheelbarrow sounded from across the fence and I looked up to see Grim heading towards his shed. His barrow was full of boxes half covered by a tarpaulin. When he saw me he scowled, let go with one hand and pulled the tarpaulin all the way across, hiding the contents. I watched him wrestle the load across the uneven ground. When he finally reached the shed he fumbled with the double padlock on the door.

I couldn’t help wondering what was in those boxes. And more to the point, why he was being so secretive about whatever was in his shed. Maybe he was a bank robber and kept all his money in there, or a spy sending out secret messages in the dead of night.

I sidled along the fence, pretending to pick caterpillars off leaves but all the while keeping my attention fixed on Grim.

‘Tomas,’ Grandad called. He shook his head and frowned. ‘You’ll lose your nose in that there bush in a minute.’

I stepped away, trying to act like I hadn’t been spying.

‘You haven’t been over there messing about again, have you?’ Grandad asked, giving me a hard stare.

‘No way! What’s Grim been saying now?’ I said, launching into full-on defence mode.

‘Now hold your horses. No one’s been saying nought. And who’s “Grim” when he’s at home?’

I looked sheepish and nodded over the fence.

Grandad sighed. I could tell he was going to do that thing where he stuck up for people, even people who totally didn’t deserve it in my opinion.

‘Just leave him alone, OK? He’s had a hard time lately, poor Jim, so I’ve heard. He lost his wife a while back and his only son is off in Australia.’

‘But that’s no reason to be having a go at us all the time, is it?’ I snapped, even though I could feel another maggot joining in the squirming in my tummy as I said it. I couldn’t help feeling bad about his wife. But then again I couldn’t imagine Grim with a cosy home and a family. He was way too prickly for all that.

Grandad looked at me. His eyebrows wiggled higher up his forehead like two little fluffy grey caterpillars. I was still poised as if I was ready for battle right then and there.

‘Just leave him alone. OK, Tomas?’

I mumbled something about it not being us who’d started it. And the caterpillars marched back downwards as Grandad gave me a warning stare.

As he turned to go into the shed I saw Flicker dart past one of the tendrils on the dragon-fruit tree and into the heart of it. He reappeared a minute later, but before I could peer in to look closer, Grandad called out again.

‘Come on, Chipstick, let’s take another look in that old book we found, see if we missed something about your tree.’

Not wanting to draw attention to Flicker, who was now rapidly changing colour, I hurried over to Grandad.

‘Fancy crawling into a dirty corner?’ he said with a little grin.

‘What?’ I said.

‘I knocked the book off the counter earlier and it’s gone behind some boxes.’

I followed him into the shed.

Grandad pointed under the counter that ran along one wall. ‘Just at the back there,’ he said.

I bent down and shuffled forward on my hands and knees, looking for the book. It was an old encyclopedia of plants that had been left behind by the woman who’d lived in the house before Nana and Grandad. I’d already been disappointed once by what I’d read in it. You see, it talked about this legend where dragons were supposed to breathe out the dragon fruit. But it didn’t say anything about dragons actually hatching out of the fruit. Still, maybe Grandad was right about it helping us work out what was wrong with the tree. It was definitely worth a look, even if it did mean scrabbling about on the floor.

‘What is all this stuff under here?’ I asked, dragging out box after box and trying not to think about the size of the spiders that had no doubt taken up residence in this neglected corner of the shed. They’d probably wear battle armour and ride mice.

‘Dunno, most of it belonged to the lady who lived here before us. Elvi, I think her name was. The trouble is,’ Grandad went on, ‘when someone dies and they don’t have family about to sort stuff, things get shoved in corners and forgotten. Nobody wants to spend time going through it all. We’ve stored what we can – photos and stuff. But I have to admit I haven’t got round to looking through all this.’

I reached in further and felt my way along. The tips of my fingers touched something. I felt the leathery spine and the embossed lettering and remembered how it had reminded me of some kind of ancient spell book.

I closed my eyes, ignored the mental images of weightlifting spiders and stretched out till I could get my hands round it enough to pull it free.

As I lifted it, something that had obviously been tucked between the pages fell out. I picked it up and crawled out. Grandad took the book from me and laid it on the counter. He flicked through the pages till he found the one about the dragon-fruit tree. His finger traced the words, hovering over certain passages.

‘All it says here is be careful not to overwater it, so maybe it likes things dry, unlike the rest of the garden. I guess that makes a certain amount of sense, given it says it comes from Mexico originally. Perhaps we’ve been a bit too generous with the water sloshing?’

But I was only half listening. I was too intent on the piece of paper in my hand. I’d known the instant I saw it that this was something important. My fingers seemed to buzz just from touching it. Along the edge of the paper was curled a drawing of a dragon’s tail. When I started to unfold it I could see the whole shape of the creature, stretching out across the page. And within its wings was a map.