And now, the storm. It took days to gather. The first sign Avatak noticed was a steadily rising swell that lapped against the ship’s hull, gathering into white-flecked waves that rocked the vessel. That was all: the air was calm, the sky clear of cloud, only the sea was restless. But the sailors watched the weather anxiously, muttering in the coarse Persian that was their common argot that it was not the season to expect such conditions. Then a lid of feathery cloud covered the sky, and descended, horribly quickly. Lost in grey fog, the sailors began to make fast the sails and lash loose goods and fittings in place. The captain brusquely told the passengers to stay in their cabins, and they were given a couple of days’ ration of biscuits and beer to keep them happy.

Pyxeas had barely stirred from the cabin anyway, and complained only when the rocking of the ship, the howl of the wind, disturbed his concentration. Avatak spent a lot of time standing at the window, holding down the scraped leather cover to keep the draught out of the cabin. He watched the sea surge, and the wind tearing at the crests of the waves, scattering spray that flew horizontally. He began to see strange sights in that sea, trees uprooted, a dead cow floating with its legs stuck up in the air – debris from the land where the storm must already have struck. He saw nestspills too, their fragile craft smashed, bloated bodies drifting in rags.

Still the seas rose, still the winds gathered until no man could stand on deck, still the clouds raced over the sky, dark and menacing. And suddenly the rain lashed down, coming in horizontally, hammering against the hull, leaking through the slightest gap. It washed into the cabin and over the scholar’s pages, evoking furious complaint, unless Avatak held the leather cover firmly in place with both hands.

Then, suddenly, the storm went away. The sea was calm again, the rain vanished, the winds dropped. Avatak and Pyxeas exchanged puzzled glances; this did not seem natural. The air felt warmer than it had done for days, warm and humid, sticky. Avatak cautiously peered out of his window. By a peculiar golden light he saw a flat sea littered with debris – some of it having come from the ship, barrels, what looked like a snapped mast – but, further out, there was a mass of cloud, low, racing by.

‘The eye of the storm,’ Pyxeas said, marvelling. ‘Remarkable. I’ve heard travellers tell of it; I never expected to experience it myself. But don’t relax, Avatak; the storm is not done with us yet.’

He was right. Soon that wall of cloud roared towards the ship, and they were plunged back into the storm as abruptly as they had left it.