The ferry had left Liverpool at half past ten in the evening and by the time she found her seat in the forward lounge it was already moving, the city lights sliding away to the stern and the darkness of the river opening ahead, and the engines which had been a vibration underfoot while the ship was in the dock were now becoming a sound, a low and continuous sound that she could hear through the floor and through the seat and through the air of the lounge, the sound of very large engines working at their steady pace, a sound that was somewhere between a hum and a rumble and that had a particular quality of completeness, of being the full background of everything, the sound inside which all other sounds occurred.
She had made this crossing many times. Dublin to Liverpool and Liverpool to Dublin, back and forth over the years, for various reasons at various stages of her life, and the overnight crossing was her preference over the day sailing because the overnight gave you something the day sailing did not, which was the experience of the sea at night, the Irish Sea in the dark with the ferry's engines beneath you and the sky above and the water going past.
Her first crossing had been in the other direction, Dublin to Liverpool on a night ferry of an earlier generation, a smaller and older ship that had rolled in the autumn swell and that had not had the reclining seats of the current ships but only the upright seats of an old-fashioned coach, and she had sat in an upright seat for the eight hours with her coat around her shoulders and had not slept and had arrived in Liverpool at half past six in the morning feeling the way that young people felt after a sleepless night, which was not much different from the way she felt after sleeping, the resilience of the young body being such that the night without sleep was simply the night without sleep rather than a deprivation. She had been twenty-two and she had been going to Liverpool for the first time in her life, for the start of a job that she had been offered and had accepted on the basis of a single visit to the city, and the crossing had been the beginning of the departure from Ireland, the point at which the decision was made real by the movement of the ship away from the pier, and she had stood on the deck of the old ferry as it pulled away from the dock in Dún Laoghaire and had watched the lights of Dublin diminish and had felt the particular feeling of leaving that crossing the Irish Sea in that direction produced, a feeling that was not quite sadness and not quite excitement but something in between them, the feeling of a person in transit who has not yet arrived anywhere.