She had the top flat in Dereham Court, a new luxury block not far from his own home and he could hear cool music drifting from a half-open window as he parked the green Mini-Cooper and went up the steps into the hall.

She opened the door to him herself, a tall, elegant blonde in a superb black velvet trouser suit who looked startlingly like her public image. When she greeted him, he might have been the only person in the world.

‘Why Nick, darling, I was beginning to think you weren’t going to make it.’

He took off his coat and cap and handed them to the maid. ‘I nearly didn’t. First evening off for a fortnight.’

She nodded knowingly. ‘I suppose you must be pretty busy at the moment.’ She turned to the handsome greying man who hovered at her elbow, a glass in one hand. ‘Nick’s a detective, Frank. You’ll know his brother, by the way, Jack Miller. He’s a director of Northern Television. This is Frank Marlowe, my agent, Nick.’

Marlowe thawed perceptibly. ‘Why, this is real nice,’ he said with a faint American accent. ‘Had lunch with your brother and a few people at the Midland only yesterday. Let me get you a drink.’

As he moved away, Joanna took Miller’s arm and led him towards a white-haired old lady in a silver lamé gown who sat on a divan against the wall watching the world go by. She had the face of the sort of character actress you’ve seen a thousand times on film and television and yet can never put a name to. She turned out to be Mary Beresford, Joanna’s aunt, and Miller was introduced in full. He resisted an insane impulse to click his heels and kiss the hand that she held out to him, for the party was already turning out to be very different from what he had imagined.

That it was a very superior sort of soirée couldn’t be denied, but on the whole, the guests were older rather than younger, the men in evening wear, the women exquisitely gowned. Certainly there were no swinging young birds from the television studios in evidence – a great disappointment. Cool music played softly, one or two couples were dancing and there was a low murmur of conversation.

‘What about the Rainlover then, Sergeant Miller?’ Mary Beresford demanded.

The way she said sergeant made him sound like a lavatory attendant and she’d used the voice she kept for grand dowager parts.

‘What about him?’ he said belligerently.

‘When are you going to catch him?’ She said it with all the patience of an infant teacher explaining the school rules to a rather backward child on his first day. ‘After all, there are enough of you.’