Beckwith spoke to my questioning look: ‘Connolly boys. Dublin originally. The boy Angus was given away. He’s, er…’—he pointed at his temple—‘soft in the head, miss. Wound up in Stromness, brung up Orcadian Scot. Him and Declan here both got on the wrong side of it, both transported. Thing is, miss, they put em both on the same ship. Marquis of Huntley. Who knows, someone in the Home Office with a sense of humour. Started beatin each other the minute they clapped eyes an they haven’t stopped since. Good workers, though.’

‘A wonder they find the time,’ I muttered.

‘Young Declan’s actually very good to the other un. But if they starts millin on board just let em go. Won’t involve yer.’

Declan slapped Angus genially on the shoulder; they grunted and returned to their work.

Beckwith guided me below, where I found the large front cabin had been reserved for me. Of the four bunks amidships, the upper on each side had been removed and the remaining cots were curtained off: the master’s on the starboard and my father’s on the port side. A handrail had been installed from the bedside to the stepway at the foot of the cots. It led up the three stairs to the galley, to guide my unseeing father. His cot had been built up on a timber box at waist height, presumably so he could find it in the dark without having to stoop.

The Connollys, I learned, had rigged hammocks in the hold among the crates and casks, too cramped to swing without bumping the stores. A government-issue blanket had been thrown on each, their boots and some loose clothing scattered underneath.

That left only Dr Gideon, who had taken up the captain’s cabin because of his need for working space. Beckwith told me this in a reverential whisper. I was not invited to inspect Dr Gideon’s quarters: clearly a man of such eminence should never have to put up with a woman traipsing through his private domain.

The boat smelt, not unpleasantly, of timber and resin and hemp, and the air in the small spaces below decks was dense and still. Sound from above did not penetrate far into this world: the timbers muffled it and the gloom created a sense of secrecy.

In the middle of the day I took the mare on her final errand, to my father’s shack. I found him washed and shaved, a circumstance that filled me with optimism. A plate dripping on a rack told me he’d eaten. He made no attempt to bring a bottle with him, though I could tell through long familiarity that he had been drinking. The enormous care over syllables, the exaggerated precision of trivial movements like locking the door.