‘You going to let me come, old man?’ said Maxwell, holding on to Anton’s elbow.

‘You can come to the station if you like. I can’t guarantee anything. What about you, Emerald? Do you want to see your brother?’

‘To see Amos? Of course I do.’

‘That does it,’ said Maxwell. ‘If she goes, I go. Who the hell else is going to look after me here?’

They went by mule up to the station at Colón, which was little more than a platform built up on the side of Main Street. There was some wrangling with the guard, who was unwilling to take Emerald on board the caboose attached to the back of the train.

‘It’s no place for a …’ He seemed to struggle for the word.

‘For a lady?’ said Emerald. ‘I’m no lady. I’ve ridden worse than this pile of rust. I’m getting on.’

Maxwell fished two silver dollars out of his waistcoat pocket, pressed them on the guard, and the deal was done.

‘You saw that, Heideck. I’m claiming those two dollars back from Pop Dawson when I get home.’

‘As God is our witness,’ said Anton. ‘All aboard.’

The train took them through the jungle on a recently completed line, just north of the man-made lake. The rain had eased off and the sun was shining on the wet green of the jungle, though to Anton’s surprise Maxwell seldom lifted his eyes from his book, The Return of Sherlock Holmes.

‘You don’t know what you’re missing,’ he said.

‘What?’ said Maxwell, looking up. ‘It’s good, this, you know. I’ll lend it to you when I’ve finished.’ He took a bottle of brandy from his bag and handed it round.

On the open platform at the rear of the caboose, Anton could see where the undergrowth and rocks had been scraped out by giant slides; it was a mud glacier in whose terminal moraine lay the bones of men. Eventually they came to the nine-mile stretch of the Culebra Cut itself and the guard had the train stopped so they could look down.

Hundreds of feet below they could make out the tiny figures of the labourers on the floor of the Cut, from whose bed rose clouds of sulphur and boiling steam. Small engines puffed and shunted like overwound toys. Unworldly sounds drifted upwards – the rumble of the dirt trains, the metallic ring of drill on rock and the boom of dynamite that reached them only after the smoke had begun to rise.

That evening they found Amos in a settlement on the outskirts of Panama City. His lodging was divided by a curtain into parlour and sleeping area, though the whole thing was only the size of a maid’s room in Vienna. The walls were papered with pages torn from illustrated magazines. There was a cooker on the veranda out front, on which Amos began to make dinner while Maxwell went in search of liquor.

Amos declined the offer of beer when Maxwell returned, but told Anton about his life in the locks where he was now working. His job was driving rivets into the concrete wall; with four other men he stood on a plank held up by chains. This makeshift scaffold covered the face of the empty lock to a depth of eighty feet in a series of platforms, like a giant and unstable rope ladder suspended from the rim. If one plank fell, it would take others with it. Amos said he preferred the risk of falling to working on a steam shovel in the Cut where he was for ever being told to dive into the slime to free the suction pumps.