And now there would be a human with them, an unexpected hitchhiker on their journey through the ages. Based on Homo sapiens’ seemingly relentless race towards self-destruction, she couldn’t help feeling he would also be the last human – though at the same time she refused to be so pessimistic as to believe Cheng was already dead. She had to give him a chance, even if only in her mind. ‘Goodbye, Cheng,’ she whispered. ‘A-plus from me, no question.’

Eddie entered the steep tunnel, blocking her view of the hidden wonder. She looked ahead as he used the gun’s light to illuminate their way. ‘How long have we got?’

He checked his watch. ‘About forty seconds.’ A pause, then he continued, with uncharacteristically exposed emotion: ‘If it goes off, we . . . we won’t have too long to worry about it. But I want you both to know, well . . .’ A crooked grin at Nina. ‘Ever since I first met you, all those years back? You’ve caused nowt but trouble.’

‘Gee, thanks.’ But she knew he was joking. Her eyes started to well with tears.

‘You changed my life,’ he went on. ‘For the better. I’ve seen things nobody ever imagined, done things I never dreamed of doing – saved the world a few times an’ all. I couldn’t have done it without you. And I wouldn’t have had the most amazing daughter in history either.’

‘Aw, Dad,’ said Macy, blushing despite the tension.

‘Well, yeah, I kind of had to be involved in that part,’ Nina said, smiling. ‘And y’know, you changed my life too. If I hadn’t met you – well, I’d have died seventeen years ago, so there’s that! But . . .’ She looked him in the eye, pulling herself a little closer. ‘I don’t need to tell you how I feel about you, do I? You already know.’

His own smile widened. ‘Yeah, I know.’

‘Plus,’ she went on, more quickly, ‘there’s a limit to how many times I can say “I love you” in the next ten seconds!’ She turned towards her daughter. ‘But Macy, however long I had, I couldn’t say it often enough. So just once’ll have to do. I love you. I love you both, so much.’

Macy halted, grabbing them in as big an embrace as she could manage. ‘I love you both too!’ She squeezed her face against them, muttering under her breath, ‘We’re not gonna die, we’re not gonna die, we’re not . . .’

Eddie kissed Nina, the couple in a moment reliving every other they had ever shared. Then they closed their eyes, holding their daughter to them—

Nothing happened.

Seconds passed. Eddie cautiously opened an eye and peered at his watch. ‘We’re five seconds past . . . ten seconds . . .’ He looked back, listening for any sounds echoing up the tunnel. Only silence reached his ears. ‘The conventional explosives didn’t go off . . .’