Collis looked around him. ‘You know something?’ he said hoarsely. ‘They said it couldn’t be done. When I first swore that I’d take a railroad over the Sierras, they said it couldn’t be done. Well now, dammit, we’re right on the edge of showing them just how backward and blind they were. We’re almost there, Charles. Can you understand what that means? These mountains I used to look at from my back veranda in Sacramento, we’ve licked them and we’ve licked them good.’

Charles took his arm. ‘Come on, Collis. Let’s go find ourselves a drink. You look like this heat and this dust aren’t doing you any good at all.’

Collis wiped his mouth with the back of his hand. His face was glistening with sweat, and he looked appallingly haggard.

‘Yes,’ he said, ‘you’re right. But you just make sure I’m the first to see this hole blasted right through. You hear me? I don’t want any blasting without my knowledge.’

‘Okay, Mr Edmonds,’ promised the foreman.

Together, Collis and Charles walked back down the tunnel until they were out in the daylight again. They crossed the tracks to Charles’s hut, and Charles unlocked the door and ushered Collis inside. There was a rough-and-ready living-room, with a carpet, and a chaise longue, and an ugly mahogany cabinet, and even a lithograph of San Francisco Bay; through a curtained doorway, Collis could see a brass bed and a set of framed daguerreotypes of nude French models.

Charles went to the cabinet, produced another bunch of keys, unlocked it, and brought out a bottle of bourbon. ‘You know, Collis,’ he said, filling up two glasses, ‘you really ought to take it easier. You don’t look well.’

‘I’m not sick,’ said Collis.

‘Maybe you’re not now, but if you go on pushing yourself this way, you soon will be. You mark my words, if you keep working as hard as you are now, without a let-up, then you’re going to be lying in your grave by the time you’re forty.’

Collis sat down and took his drink. ‘Do you really think that matters?’ he asked Charles.

Charles sat down beside him. ‘Of course it matters. You’re the inspiration behind the whole of this railroad. You’ve changed the history of this nation in a matter of a few years, almost single-handed. How can you say it doesn’t matter?’

‘Hannah should have been here today, Charles. Hannah and two young children of mine.’

Charles looked uncomfortable. ‘Well,’ he said. ‘That’s the way life is.’

Collis put down his glass and rested his head in his hands. When he spoke, his voice was graver and more measured than Charles had ever heard it.

‘I want to finish this railroad, Charles, because I can’t go back. But if there was any way in which I could trade this railroad, and all its locomotives, and all its ties and its spikes and its rails — if there was any way in which I could trade this railroad for one day with Hannah, one more day with Hannah, then I would do it gladly.’