And sitting there in the halted train it occurred to her that what really excited Mark was the business of transformation. Descending on Liz, ruffling her feathers, laughing at her seriousness, magicking her into a bird of paradise. If she had lived in an airy modern flat overlooking one of the London parks, with wardrobes full of exquisite designer clothes, then she would have held no interest for him at all.

She really had to end it. She hadn’t told her mother about him, needless to say, and in consequence, whenever she stayed the weekend with her in Wiltshire, she had to endure a well-intentioned homily about Meeting Someone Nice.

“I know it’s difficult when you can’t talk about your job,” her mother had begun the night before, lifting her head from the photo album that she was sorting out, “but I read in the paper the other day that over two thousand people work in that building with you, and that there are all sorts of social activities you can do. Why don’t you take up amateur dramatics or Latin American dancing or something?”

“Mum, please!” She imagined a group of Northern Ireland desk officers and A4 surveillance men descending on her with eyes blazing, maracas shaking, and coloured ruffles pinned to their shirts.

“Just a suggestion,” said her mother mildly, and turned back to the album. A minute or two later she lifted out one of Liz’s old class photos.

“Do you remember Robert Dewey?”

“Yes,” said Liz cautiously. “Lived in Tisbury. Peed in his pants at the Stonehenge picnic.”

“He’s just opened a new restaurant in Salisbury. Round the corner from the Playhouse.”

“Really?” murmured Liz. “Fancy that.” This was a flanking attack, and what it was really about was her coming home. She had grown up in the small octagonal gatehouse of which her mother was now the sole tenant, and the unspoken hope was that she should return to the country and “settle down,” before spinsterhood and the City of Dreadful Night claimed her for ever.