Her mother was sixty-three years old. Her health was excellent. It was only her mind that was dying.

Employing Mrs. Gustafson to stay with Mrs. Havers during the day was, Barbara knew, only at best a temporary and unsatisfactory measure. Seventy-two years old herself, Mrs. Gustafson had neither the energy nor the resources to care for a woman whose day had to be programmed and monitored as carefully as a toddler’s. Three times already Barbara had come face-to-face with the impediments inherent to giving Mrs. Gustafson even limited guardianship over her mother. Twice she had arrived home later than usual to find Mrs. Gustafson sound asleep in the sitting room. While the television shrieked out a programme’s laugh track, her mother floated in a mental fugue, once wandering at the bottom of the back garden, once swaying aimlessly outside on the front steps.

But the third incident, just two days ago, had rocked Barbara severely. An interview connected to the Maida Vale rent boy case had brought her close to her own neighbourhood, and she had gone home unexpectedly to see how things were going. The house was empty. At first she felt no panic, assuming Mrs. Gustafson had taken her mother for a walk and, in fact, feeling quite grateful that the older woman was even up to the challenge of controlling Mrs. Havers in the street.

Gratitude disintegrated with Mrs. Gustafson’s appearance on the front steps less than five minutes later. She’d just popped home to feed her fish, she said, and added, “Mum’s all right, i’nt she?”

For a moment, Barbara refused to believe what Mrs. Gustafson’s question implied. “She isn’t with you?” she asked.

Mrs. Gustafson raised one liver-spotted hand to her throat. A tremor shook the grey curls of her wig. “Just popped home to feed the fish,” she said. “No more’n a minute or two, Barbie.”