Living at Number Sixteen Evelyn Mews, Tilda often thought, was like living in a poem. Number Sixteen was a townhouse of bright whitewashed brick with black shutters and a glossy black roof. The slender chimneys were black too, as was the lamppost that watched over Tilda at night, bending its glowing head through the trees. In the morning the sparrows twittered in the leaves and the sun shone in pools in the shallow gutters.

Tilda had moved into Evelyn Mews three months ago, and since then she had adopted certain habits. She took to wearing gloves to work, taper-fingered black kidskin. At breakfast she poured her milk from a curved china pitcher instead of the bare canon. At bedtime, she read the poetry of John Keats, occasionally glancing at the sliver of moon through her curtain, which winked as if in sympathy. She loved these Romantic whisperings from a bygone time—the zephyrs and nightingales and Grecian urns; she loved the smell of the splendid leather-bound volume, which she mark…