The one thing he does remember from school is that continental drift was happening in the Cretaceous period. The land masses of the Americas were joined to Europe, Africa and Asia, which all formed some supercontinent, the name of which escapes him. Pang? Pangle? Pangea? Something like that. They could be anywhere in the world. They could be in the spot of what later becomes the Atlantic Ocean or Beijing or bloody Battersea Dogs Home for all he knows. That’s happening now though. The continents are moving apart right now. They could walk or drive for thousands of miles and recognise nothing. The coastlines would be completely different. Everything is different but exactly how you would expect it to look. Get an artist to read some dinosaur books and ask them to paint a picture from the image formed in the mind and this vista is what you would get. Swampy, hot and green.

The irritation Safa felt at the lack of protocols soon passes. The feel of the sun is gorgeous. The view is amazing. The air is so thick and clean. She breathes in a deep lungful and almost feels giddy for a second. Ben said there was more oxygen here but then Roland said they had been medicated. She watches Harry scoping the wildlife down in the plains then glances over to Ben and smiles at the look of rapture on his face. He seems so different again. Like he’s come alive and can’t move his head fast enough to take everything in.

She motions for Harry to walk down the side of the bunker to join Ben and she stares down as mesmerised as he at the commanding view, which no person ever born could ever tire of seeing. Safa was right. Ben’s mind opens completely. Thoughts whirl and spin through his brain as he tries to gain perspective and context.

‘Up?’ Ben blinks back to the now and looks at Harry motioning up the bank that rises behind the bunker.

‘We should,’ Safa says, turning her back on the valley to stare up at the bank. How can she do that? How can anyone turn away from that sight? ‘Ben?’ she calls.

‘Coming,’ he mutters.

This time Harry takes the lead and threads a staggered route up the steep bank. Within minutes, Ben is breathing hard with sweat beading on his face.

‘Moss,’ Harry says from up front.

‘What?’ Safa asks. The big man comes to a stop and points over at a collection of rocks and ferns.

‘Moss,’ Harry says again.

‘Okay,’ Safa says slowly.

He looks at her then at Ben. ‘Moss grows on the northern side. That way’s north,’ he says, pointing back towards the bunker.

‘Oh right,’ Safa says casually with the corners of her mouth twitching.

‘What?’ Harry asks.

‘Nothing,’ she says lightly. ‘Good skills.’