The crew backed water to a safe distance and heard a cry of triumph from the deck of the Felicity. But Gus, craning round, saw that the Shenandoah was already on the move.

‘The captain’s seen,’ he called. ‘He’s moving up.’

In a few moments the Shenandoah, with the advantage of steam, was close enough to bring her guns to bear on the defiant whaler and Captain Waddell’s voice boomed across the water.

‘Surrender, or I’ll send you to the bottom.’

‘I’ll see you damned first!’ The wild-haired man leapt to one of his guns and pulled the trigger. There was a click, but nothing more. Swearing, he flung himself at the other, with the same effect. He raised his pistol, levelled it at Mason and fired. Once again, there was nothing but the click of metal on metal.

Mason began to laugh. ‘Someone’s had the sense to remove the charges. Thank God for that!’

For a moment the master of the Felicity dithered, then threw down his useless weapon and raised his hands. ‘Sold down the river by my own crew! That’s it. You win.’

They took him on board and the reason for his show of defiance immediately became clear.

‘He’s been on the rum,’ Mason said. ‘He’s three sheets to the wind if ever I saw it.’

As usual each ship was ransacked for anything useful. By nightfall all had been stripped but a problem remained. There were far too many prisoners to be accommodated on the Shenandoah. Waddell solved it by ransoming two ships, making the masters sign an undertaking that the owners would pay to get them back and that they would say nothing about the Shenandoah’s current position. The prisoners were then transferred to those ships and they sailed away. Then the remaining ships were fired.

Gus, as usual, had found a position close to his mentor, Mason, and heard him say, ‘It’s a terrible thing, to see so many good ships go up in smoke – but you have to admit it’s an unforgettable sight.’

It was true. The ships had been denuded of sails and ropes, so they drifted without direction on the currents and as the flames roared skywards every spar and yard was outlined in fire against the blue-grey of the ice.

Leaving the burning hulks of the whalers behind, the Shenandoah headed still further north, in search of what was rumoured to be a large fleet in the Bering Sea.

‘Look at this, Gus,’ Mason said one morning. ‘We are now within the Arctic Circle. That’s Russia on our starboard bow and Alaska to port. It’s not often you can see two continents at the same time.’

The information meant little to Gus. He was much more interested in a flock of seals, basking on the ice floes that drifted past.