One of the rocks, though, looks longer than I’m used to. Greener, knobbly. And is it … is it moving?

‘Oh no, no, no,’ I murmur to myself, and I scramble to my feet again. As I watch, the rock rises up a little more and a yellow eye blinks at me slowly as Cuthbert shoves his snout out of the river and starts gliding towards me.

‘Friend of yours?’ says Mola, but my throat is too dry to answer. I’m thinking of my options. I could dream up a Nerf gun? They were pretty effective, only …

Hang on! What about a real gun?

‘Good idea,’ says Fit Billy who has appeared beside me, unexpectedly, just like in a normal dream. Instead of dumbbells, in each hand he holds a huge gun. ‘Can I recommend this?’ He tosses me a gun, which clatters at my feet. ‘A classic Thompson sub-machine-gun. Standard US Army issue throughout World War Two. That model’s the M1A1, slightly lighter. You wanna be careful with it, son. Canny firearm, that is!’

‘Thanks, Billy.’ I crouch to pick it up. When I look again, Billy has gone, but Cuthbert is now coming out of the water. The machine-gun is about a thousand times heavier than Seb’s plastic Nerf gun and I heave it to my shoulder.

‘All right, you! I’ve got you now.’ I squint through the sights, making sure the crocodile is exactly where I want him, and squeeze the cold metal trigger gently, then harder, then harder …

The closer Cuthbert gets, the better my chances of hitting him; but, if I miss, his chances of getting me increase hugely. If he does that, I’ll wake up, and I can’t risk that in case I don’t get to sleep again.

I let the crocodile get closer and closer. Mola is a few metres away, further up the bank. ‘Careful, Dream-boy!’ she warns.

Cuthbert’s jaws open: a direct hit, right in the gob, is what I need. One last squeeze of the trigger, and

BAM BAM BAM BAM BAM BAM BAM BAM BAM BAM BAM BAM BAM BAM!

The noise is painful in my ears, but I hold my arms and shoulders steady, keeping the gun aimed directly at Cuthbert. I let off another round.

BAM BAM BAM BAM BAM BAM BAM BAM BAM BAM BAM BAM BAM BAM!

I lower the gun, expecting to see the corpse of a huge crocodile lying in the shallows by the river bank.

‘I say, old boy. Doesn’t seem to be working, does it?’ drawls Cuthbert. ‘Daresay that’s the thing with dreams, hey? Don’t always do what you want! Ah well, tally-ho!’

He runs towards me on his stumpy legs, and I drop the gun. I’ve backed up to the steep bank of the canyon, but I can’t get up it because I can’t get my hands on the handholds, and …