I pulled the hinge open carefully, ready to spring away if anything moved. ‘Look at these wires and this shiny sheeting. Some electrical gubbins, isn’t it? And there was a little puddle of water here before. The cold spot was just here.’ I showed him. ‘This has to be connected to the weather stuff.’

Sam crouched. ‘Weird. Might be an experiment.’ He poked a finger into the spaghetti wires that spilt down the outside edges, lifting carefully.

‘Hey, don’t electrofry yourself to death!’

He ignored me and let the wires down gently. ‘Copper wire. And look at these.’ He pointed at some tinier wires in one corner. ‘Thin as hairs.’

I whistled. Hadn’t even noticed them.

‘So something to do with electrical conductivity do-dahs,’ he said. ‘You got a little shock. You said there was crackling, so that must have been static.’ He tapped the blue glass. ‘Yep. This is a solar panel. He must be running something off the sunlight.’ He squinted up into the tree and a gust of wind blew his hair upside down. ‘Look. It’s hidden in all these trees, but there’s a bare place where the sun gets through quite well.’

I grinned. ‘Knew your savvy would come in handy!’

Sam blushed. ‘Yerp, well … my auntie’s got some on her roof. Exactly the same blue.’

Sam stood up and so did I. He looked down at the box. ‘A bat could move quickly.’

‘Nope. It was too fast.’

‘Some kind of insect?’

I shook my head. ‘It was more like a piece of wind.’

He laughed. ‘Wind doesn’t come in pieces. It’s just moving air.’

‘Well, this isn’t just a cage – it looks too clever and complicated for that.’

Sam nodded. ‘Yah, he must be feeding electricity into this for a reason.’

‘Maybe it’s a life-support system!’

Sam widened his eyes at me. ‘Cool!’ he said, nodding slowly. ‘Of course.’

‘For an electrical creature! I got two electric shocks, so that makes sense. An experiment that went wrong!’

Sam’s eyes were wild. ‘An electrical creature?’

‘He must have bred it – you know, like people say.’

He grinned. ‘That’s just ill.’

‘There are electric eels, aren’t there?’ I said.

‘Yerp. So …?’ (Sam never ever says the word ‘yes’. Not unless he’s spitting mad.)

‘Maybe he got one and experimented on it. That old man said he mangles things. Maybe it’s a mangled electric eel.’

‘On dry land?’ Sam said. ‘Heh! Yah, Alfie, not one of your better ideas. There’s no creature that’s made of only electricity.’ He frowned at me sceptically. ‘Are you really sure you saw this thing?’

I remembered something else. ‘After it escaped, the box clicked and ticked, like gas fires when you switch them off. Like metal contracting.’