At the repetition, Esther nodded once more. And then she did something else, something Mrs Bannister had not bargained for. She opened her own mouth, and stood tense for a moment, her lips trembling, her throat working under the smooth childish skin. Then a sound came from between her lips.

It was not the sort of sound Mrs Bannister had ever heard before. It was something between a groan and a cheep, ill-pitched and shapeless, though produced with mortal effort. But it was a sound, a single sound: to an eager mind, it was a word; and, with great love and faith, it was the word: ‘Fire’.

By contrast with this moving moment, which seemed to put a seal of hope upon the future, the Atlantic crossing to New York was a frightful ordeal.

There were head seas all the way over, and it was rough – far too rough for a medium-sized ship trying to keep to a seven-day schedule. The 7,000-ton liner was thrown about with great violence and spite, and so were her passengers; and so, in an A-deck outer cabin, was Esther Costello who, pitifully seasick, terrified all the time, weeping with doubt and fear, lost much human ground during the nine days at sea.

There was nothing that Mrs Bannister or the stewardess could do for her, save watch her all the time, and try to prevent her hurting herself. There was no conceivable way of explaining, to a blind and deaf child who had seen nothing bigger than a village pond, that here was the sea, and this was what it did to ships and to the people in them. There was no way of explaining that it was not the earth which was heaving and lurching with such drunken fury, but something else which, though wickedly active, was still permissible within nature. They simply had to make her endure, chancing the fact that she would feel herself betrayed by the senseless change from comfort to violence, and might lose faith and heart, and that all the benefits stored up in the previous weeks might ebb away again.

“If this was happening to me,” said Mrs Bannister to the stewardess, as together they watched Esther clinging to her bunk in terror, while the ship, poised giddily on the crest of a huge wave, swayed downwards towards its yawning trough: “if this was happening to me, and I didn’t know what it was, I’d think people were punishing me on purpose …”

She did what she could, by her presence and her warm touch, to convey to Esther that she was not in disgrace, that care and love were still wrapped round her, that they were all undergoing this crude torment together. But many times, when the girl cried out to feel the world beneath her rocking, it seemed as though the young heart, newly cherished, was being given too sudden and too brutal a test.

Mrs Bannister spent virtually the whole voyage in the cabin, leaving it now and then for a brief walk round the heaving, deserted deck, and then going below to shelter again. She took all her meals with Esther. Only on the last day, when the westerly gale died, and the shelter of the American coastline steadied the ship again, did she emerge from the self-contained, painful world below.