Alleyn looked at his watch. It was just on noon. He suggested that they return to the mainland and call on the rectory. The tide was coming in and they crossed the channel by dinghy. There was Alleyn’s car by the jetty with his luggage in it. If things had gone according to plan, he would have been half-way to Troy by now.

They left it where it stood. The rectory was a five minutes’ walk along the front. It stood between a small and charming Norman church and Dr Maine’s Convalescent Home: a pleasant late-Georgian house with the look, common to parsonages, of being exposed to more than its fair share of hard usage.

‘It was a poorish parish, this,’ Coombe said, ‘but with the turn things have taken over the last two years, it’s in better shape. The stipend’s gone up for one thing. A lot of people that reckon they’ve benefited by the Spring, make donations. It’d surprise you to know the amounts that are put into the restoration-fund boxes. I’m people’s warden,’ he added, ‘should have been there myself at ten-thirty for the family service. The Rector’ll be back home by now. It’s his busy day, of course.’

They found Mrs Carstairs briskly weeding. She wore a green linen dress and her hair, faded yellow, made an energetic sort of halo round her head. Her church-going hat, plastic raincoat, gloves and prayer-book were scattered in a surrealistic arrangement along the border. When Alleyn was introduced she shook hands briskly and said she supposed he’d come about this dreadful business and wanted to see her husband who was, of course, appalled.

‘He’s in the study,’ she said to Coombe. ‘Those accounts from the dry-rot people are all wrong again, Mr Coombe, and the Mayor suggests a combined memorial service but we don’t quite think – however.’

‘I’d really like a word with you, if I may,’ Alleyn said. ‘We’re trying to trace Miss Cost’s movements early this morning.’

‘O dear! Yes. Well, of course.’

She confirmed Dr Maine’s account. Miss Cost had attended the first celebration at seven o’clock and they had met at the gate. ‘She was in a great fuss, poor thing, because of my necklace.’

‘Your necklace?’