Susan puts her finger to her lips to shut me up. ‘You have done a lot, Malky. You have killed Cuthbert. Let me and Mola do this next bit.’

She beckons me to follow her towards the clump of trees. She turns back and gives a thumbs up to Mola who returns the gesture. She doesn’t seem to care at all that she is a mad, nude old lady covered in mud.

Half a minute later, and Susan and I are alongside the clump of trees, and we still can’t be seen by the group, who are about thirty metres in front of us, circling Seb and the book characters with spears and growling dogs.

Are they going to kill him? He’s only seven! He shouts out for me again, and I want to run forward and grab him, but I know that I can’t.

I hear another roar from the woods and feel another surge of fear. Then the mammoth emerges from the trees, filling my vision, and I freeze, staring.

It is twice my height and shaped like an elephant. It has a trunk with long grey bristles, two enormous, curved white tusks and a patchy, coarse coat of reddish-brown hair. It is furious, and I have no idea why it’s staying where it is.

No idea, that is, until it sees us, bellows again and starts to charge.

Susan and I shrink back, instinctively, but we need not have bothered: the beast is tethered to a tree by means of a thick, rough rope of dried plant fibres tied round its front right leg. It takes a step and is stopped instantly. Like Seb’s wrists, the mammoth’s ankle has been rubbed raw and bloody.

Susan moves towards it. What’s she doing?

But then she beckons for me to follow her, and I think of Seb, as I inch nervously forward, towards the enormous animal.

‘Quick,’ says Susan, crouching down near the tree. ‘We haven’t got long.’ She has a large, flat stone in her hand that she is using to hack at the rope where it meets the tree trunk. With every blow, one or two tiny fibres fray and snap, but it’s not breaking fast enough, while over by Seb the group is getting closer to him. They have started a haunting, rhythmic chant.

I can’t bear to watch as they lower their spears. I’m on my feet, ready to run at them, but Susan holds up her hand to stop me. ‘Not yet, Malky. Please. Wait for Mola.’ Her efforts at cutting the rope are getting slower as she tires.

‘Let me,’ I say. Susan sits back, exhausted, and I take the flat stone from her hand, bashing the remaining strands furiously.