Morning lessons were much the same as he had been used to, concentrating on reading and writing and basic arithmetic, and, once he had got over his fear, he was able to answer the questions without incurring the wrath of the teacher. It was the afternoons on the ship that he lived for. There were so many new skills that he sometimes felt he would never be able to master them all, but the captain was a good teacher, demanding undivided attention but patient where he saw there was real difficulty. Gus learned the various knots and their uses; he learned to repair sails and splice ropes; he took his turn in the galley and swabbed the decks; but what he enjoyed most were the occasions when the captain spread out his maps and charts and began to teach them the basics of navigation. For the first time, Gus saw the outline of the places his father had sailed to, the places where he still might be; Africa, the West Indies, and the coast of America.

Best of all were the times when Captain Thomas could be persuaded to talk about his own days at sea. He knew all the places he pointed out on the maps, and could describe them, so that Gus was not the only one fired with longing to see them for himself.

‘Mind you,’ the captain said, ‘things were very different in my day. We sailed what was called the triangular route. From Liverpool we’d sail south to the coast of Africa. We’d buy blackamoors there and load them into the holds; then we’d sail across the Atlantic – what they called the Middle Passage – to the West Indies or the coast of America and sell them as slaves to work on the plantations, and with the money from the sale we’d buy coffee and sugar and cotton for the mills in Lancashire and bring them back to Liverpool. Sometimes we’d bring some of the slaves back here to work as well.’

‘But that was wrong, surely.’ It was Will who voiced what was in all their minds. ‘You can’t buy and sell people. Isn’t it against the law?’

‘It is now,’ Captain Thomas replied. ‘Perhaps it should always have been, and I can’t say but what there were times, when I saw the state those poor wretches were in, that my conscience troubled me. But I was just a midshipman and the captain said it was business and it had always been done that way, so who was I to argue?’

‘But we don’t have slaves any more, do we?’ Gus asked.

‘We don’t. But there’s places in America where they reckon they can’t do without them. That’s what the war’s about.’

‘What war?’ someone asked and the question was repeated around the group.