‘This was our day to visit the Chelsea Flower Show, which was the main reason for the timing of our visit. Nancy is… was a great gardener. She’d been really looking forward to this. We were at the gates when they opened at eight this morning, and spent the whole day there until we left at around four. We were both pretty tired, but we couldn’t find a cab and decided to walk back to our hotel.’

‘Where is that?’

‘Cunningham Place, the Chelsea Mansions Hotel. Nancy said it has character…’ He stopped, swallowed and snatched a tissue from the box beside him and pressed it to his eyes. After a moment he sucked in a breath and said, ‘I’m sorry.’

‘So am I, Mr Merckle. I should let you rest.’

‘No, no. I just want to get out of this place.’

‘They’ve said you can go. Shall I take you back to your hotel?’

He nodded. ‘I feel numb, like I just want to go to sleep and wake up and discover it was all a terrible nightmare.’ He looked at her. ‘How could somebody do a thing like that? There’s no reason.’

As they walked to her car, Kathy put a call through to the Chelsea police to check on progress in the hunt for the man. They had nothing new to report.

Cunningham Place was a small square in the area where the three golden postcodes, SW1, SW3 and SW7-of Belgravia, Chelsea and Knightsbridge-converge in inner west London. Despite the impeccable real estate location, Kathy thought it a rather gloomy place, its leafy central gardens overwhelmed by the six- and seven-storey red brick terraces that surrounded it. The grandest of these was Chelsea Mansions, forming one side of the square, its bulk enlivened by Dutch gables, decorative terracotta panels, white balcony trim and an impressive central portico. Most of it appeared to be taken up by private residences, but the end bay, sporting geranium baskets and a large Union Jack from its upper balcony, had an inconspicuous brass plate by its front door announcing Chelsea Mansions Hotel, AA and RAC Approved.