As they drew further north the wind wheeled around and became more steady but Sir Dudley could keep down no food. The little ship was halfway between Scotland and Norway when the captain came to Sir Dudley, who was wrapped in a thick cloak and seated on the deck for the air.

‘We can go back or forward as you wish,’ the captain said. ‘I don’t want your death on my conscience, my lord. You’re no seafarer. Perhaps we’d best head for home.’

Sir Dudley glanced at Tradescant, one arm slung casually around the bowsprit, looking out to sea.

‘What d’you think, John?’ he asked. His voice was still faint.

Tradescant glanced back and then drew closer.

‘Shall we go back or press on?’

John hesitated. ‘You can hardly be sicker than you were,’ he said.

‘That’s what I fear!’ the captain interrupted.

John smiled. ‘You must be seasoned now, my lord. And the weather is fair. I say we should press on.’

‘Tradescant says press on,’ Sir Dudley remarked to the captain.

‘But what d’you say, my lord?’ the captain asked. ‘It was you who was begging me to turn back at the height of the storm.’

Sir Dudley laughed, a thin thread of sound. ‘Don’t remind me! I say press on, too. Tradescant is right. We have our sea legs now, we might as well go forward as back.’

The captain shook his head but went back to the wheel and held the ship’s course.

Their luck was in. The weather turned surprisingly fair, the men became accustomed to the motion of the ship and even Sir Dudley came out of his cabin and strode about the deck, his pace rocking. They had been nearly three weeks at sea and slowly, the skies around them changed. It was like entering another world, where the laws of day and night had been destroyed. John could read a page of writing at midnight, and the sun never sank down but only rested on the horizon in a perpetual sunset which never led to dusk. A school of grampus whales came alongside and a flock of tiny birds rested in the rigging, exhausted by their long flight over the icy waters. John walked up and down the length of the boat all day and most of the bright night, feeling oddly unemployed with hours of daylight and nothing to grow.

Then a thick fog came rolling over the sea, and the daylight counted for nothing. The sun disappeared behind it and there was neither night nor day but a perpetual pale greyness. Sir Dudley took to his chamber again and summoned one man after another to play at dice with him. John found himself curiously lost in the half-light. He could sleep or wake as he wished, but he never knew when he woke whether it was day or night.