The entrance hall, quiet, spacious and sunny, nevertheless had a faintly depressing air of communality that a bucket-shaped vase of dried flowers and a dull green carpet and pale yellow walls, probably chosen for their inoffensiveness, could not dissipate. As at Kentigern Gardens, there was a lift, this one with wooden doors. Strike chose to walk upstairs. The building had a faint shabbiness that in no way diminished its quiet aura of wealth.

The door of the top flat was opened by the smiling West Indian Macmillan nurse who had buzzed him through the front door.

‘You’re not Mister Bristow,’ she said brightly.

‘No, I’m Cormoran Strike. John’s on his way.’

She let him in. Lady Bristow’s hallway was pleasantly cluttered, papered in faded red and covered in watercolours in old gilt frames; an umbrella stand was full of walking sticks, and coats hung on a row of pegs. Strike glanced right, and saw a sliver of the study at the end of the corridor: a heavy wooden desk and a swivel chair with its back to the door.

‘Will you wait in the sitting room while I check whether Lady Bristow is ready to see you?’

‘Yeah, of course.’

He walked through the door she indicated into a charming room with primrose walls, lined with bookcases bearing photographs. An old-fashioned dial telephone sat on an end table beside a comfortable chintz-covered sofa. Strike checked that the nurse was out of sight before slipping the receiver off the hook and repositioning it, unobtrusively skewed on its rests.

Close by the bay window on a bonheur du jour stood a large photograph, framed in silver, showing the wedding of Sir and Lady Alec Bristow. The groom looked much older than his wife, a rotund, beaming, bearded man; the bride was thin, blonde and pretty in an insipid way. Ostensibly admiring the photograph, Strike stood with his back to the door, and slid open a little drawer in the delicate cherrywood desk. Inside was a supply of fine pale blue writing paper and matching envelopes. He slid the drawer shut again.

‘Mister Strike? You can come through.’

Back through the red-papered hall, a short passage, and into a large bedroom, where the dominant colours were duck-egg blue and white, and everywhere gave an impression of elegance and taste. Two doors on the left, both ajar, led to a small en-suite bathroom, and what seemed to be a large walk-in wardrobe. The furniture was delicate and Frenchified; the props of serious illness – the drip on its metal stand, the bedpan lying clean and shiny on a chest of drawers, with an array of medications – were glaring impostors.