one over the eight

“She’s had one over the eight,” grinned the driver. Audrey’s first impression was that the man was speaking of her, and she wondered what he meant. But he was looking beyond her, and, following the direction of his eyes, she saw a sight that first sickened and then moved her to pity. Clinging to the rails that bordered the area was a woman. She held tight with one hand, swaying unsteadily, whilst with the other she was manipulating the knocker of the front door of the house next to that place of mystery which she had left.