23 May 1939. I watched the strip of marsh fade from sight. The coast of France. The mountains took longer to disappear.

I turned when a woman’s voice cut through the noise of the crowd and the engines. ‘Come here!’

A small boy wriggled between men’s legs. A young woman chased him, burdened by the toddler in her arms. I stepped in front of the boy. He looked up at me with an expression of dismay so exaggerated that I couldn’t prevent myself from smiling.

‘Thank you, señor.’ The young woman stood the little girl on the deck to hold the rail and exhorted her, ‘Hold tight so you won’t fall.’

An elderly man made space for them. Gulls glided alongside, keeping pace with the ship. The toddler reached a spread hand towards the birds.

‘Hold on tight.’ The boy repeated his mother’s instruction.

‘Do you know, camarada, if we’re going to pass near the coast of Spain?’ she asked me.

She looked young to have two children. I felt relieved that she had called me comrade because señor repeated would have turned me into a Nationalist or a priest, a man I wouldn’t recognise.

‘I don’t think so—’

‘Will we get to Mexico today, señorita?’ the boy asked.

So she wasn’t his mother, after all. She told him not to interrupt. Her eyes were the same dark blue as the sea at the far horizon and she was fair skinned, like ...