Jonah watched her in silence, marking every detail of her tall figure with a curious sense of possession that years of intimacy had never given him with Ada.

And yet she kept him at a distance with a skill that exasperated him and provoked his admiration.

One day when he had held her hand a moment too long, she had withdrawn it with an explanation that sounded like an apology.

She explained that from a child she had been unable to endure the touch of another person; that she always preferred to walk rather than ride in a crowded bus or tram because bodily contact with others set her nerves on edge.

It was a nervous affection, she explained, inherited from her mother.